Replace osmborder with imposm/SQL (#1213)

Fixes #1156
Fixes #810
Fixes #1228

This PR replaces `osmborder`, which is no longer maintained, with `imposm` mappings and SQL code to generate borders.  Key features that were moved into the imposm/SQL layer:
1. Grouping by `osm_id` and aggregating by lowest `admin_level` value so that there's only one copy of ways that are members of multiple relations.
2. Filtering out of point features in boundary relations (typically `admin_centre` and `label` roles).
3. Move disputed boundary detection logic into SQL.

This will increase the database size slightly because of the limits of what imposm can do, as some of the filtering is done in the SQL layer after importing, rather than being done in `osmborder`.

layers/boundary/mapping.yaml

@@ -1,107 +1,34 @@
 generalized_tables:
-
-  # etldoc: osm_border_disp_linestring_gen_z2 -> osm_border_disp_linestring_gen_z1
-  border_disp_linestring_gen_z1:
-    source: border_disp_linestring_gen_z2
-    sql_filter: admin_level = 2
-    tolerance: ZRES2
-
-  # etldoc: osm_border_disp_linestring_gen_z3 -> osm_border_disp_linestring_gen_z2
-  border_disp_linestring_gen_z2:
-    source: border_disp_linestring_gen_z3
-    sql_filter: admin_level = 2
-    tolerance: ZRES3
-
-  # etldoc: osm_border_disp_linestring_gen_z4 -> osm_border_disp_linestring_gen_z3
-  border_disp_linestring_gen_z3:
-    source: border_disp_linestring_gen_z4
-    sql_filter: admin_level = 2
-    tolerance: ZRES4
-
-  # etldoc: osm_border_disp_linestring_gen_z5 -> osm_border_disp_linestring_gen_z4
-  border_disp_linestring_gen_z4:
-    source: border_disp_linestring_gen_z5
-    sql_filter: admin_level = 2
-    tolerance: ZRES5
-
-  # etldoc: osm_border_disp_linestring_gen_z6 -> osm_border_disp_linestring_gen_z5
-  border_disp_linestring_gen_z5:
-    source: border_disp_linestring_gen_z6
-    sql_filter: admin_level = 2
-    tolerance: ZRES6
-
-  # etldoc: osm_border_disp_linestring_gen_z7 -> osm_border_disp_linestring_gen_z6
-  border_disp_linestring_gen_z6:
-    source: border_disp_linestring_gen_z7
-    sql_filter: admin_level = 2
-    tolerance: ZRES7
-
-  # etldoc: osm_border_disp_linestring_gen_z8 -> osm_border_disp_linestring_gen_z7
-  border_disp_linestring_gen_z7:
-    source: border_disp_linestring_gen_z8
-    sql_filter: admin_level = 2
-    tolerance: ZRES8
-
-  # etldoc: osm_border_disp_linestring_gen_z9 -> osm_border_disp_linestring_gen_z8
-  border_disp_linestring_gen_z8:
-    source: border_disp_linestring_gen_z9
-    sql_filter: admin_level = 2
-    tolerance: ZRES9
-
-  # etldoc: osm_border_disp_linestring_gen_z10 -> osm_border_disp_linestring_gen_z9
-  border_disp_linestring_gen_z9:
-    source: border_disp_linestring_gen_z10
-    sql_filter: admin_level = 2
-    tolerance: ZRES10
-
-  # etldoc: osm_border_disp_linestring_gen_z11 -> osm_border_disp_linestring_gen_z10
-  border_disp_linestring_gen_z10:
-    source: border_disp_linestring_gen_z11
-    sql_filter: admin_level = 2
-    tolerance: ZRES11
-
-  # etldoc: osm_border_disp_linestring_gen_z12 -> osm_border_disp_linestring_gen_z11
-  border_disp_linestring_gen_z11:
-    source: border_disp_linestring_gen_z12
-    sql_filter: admin_level = 2
-    tolerance: ZRES12
-
-  # etldoc: osm_border_disp_linestring_gen_z13 -> osm_border_disp_linestring_gen_z12
-  border_disp_linestring_gen_z12:
-    source: border_disp_linestring_gen_z13
-    sql_filter: admin_level = 2
-    tolerance: ZRES13
-
-  # etldoc: osm_border_disp_linestring -> osm_border_disp_linestring_gen_z13
-  border_disp_linestring_gen_z13:
-    source: border_disp_linestring
-    sql_filter: admin_level = 2
-    tolerance: ZRES14
-
-  # etldoc: osm_border_disp_relation -> osm_border_disp_linestring
+  # etldoc: osm_border_linestring -> osm_border_disp_linestring
   border_disp_linestring:
-    source: border_disp_relation
-    sql_filter: ST_GeometryType(geometry) = 'ST_LineString'
-
+    source: border_linestring
+    sql_filter: ST_GeometryType(geometry) = 'ST_LineString' AND (disputed OR dispute OR border_status = 'disputed' OR disputed_by <> '') AND admin_level = 2
 
 tables:
-  # etldoc: imposm3 -> osm_border_disp_relation
-  border_disp_relation:
+  # etldoc: imposm3 -> osm_border_linestring
+  border_linestring:
     type: relation_member
+    filters:
+      require:
+        admin_level: [__any__]
+        boundary: [administrative]
     columns:
     - name: relation_id
       type: id
     - name: osm_id
       type: id
       from_member: true
+    - name: member
+      type: member_id
+    - name: type
+      type: member_type
     - name: geometry
       type: geometry
     - key: name
       name: name
       type: string
-    - key: boundary
-      name: boundary
-      type: string
+      # Used for disputed boundary, e.g. "Line of actual control"
+      from_member: true
     - key: admin_level
       name: admin_level
       type: integer
@@ -111,14 +38,36 @@ tables:
     - key: disputed_by
       name: disputed_by
       type: string
+      from_member: true
+    - key: dispute 
+      name: dispute 
+      type: bool
+      from_member: true
+    - key: disputed
+      name: disputed
+      type: bool
+      from_member: true
+    - key: border_status
+      name: border_status
+      type: string
+      from_member: true
     - key: maritime
       name: maritime
       type: bool
       from_member: true
+    - key: boundary_type
+      name: boundary_type
+      type: string
+      from_member: true
+    - key: natural
+      name: natural
+      type: string
+      from_member: true
+    relation_types: [boundary]
     mapping:
-      type: [boundary]
-    filters:
-      require:
-        #admin_level: ['2']
-        admin_level: [__any__]
-        claimed_by: [__any__]
+      boundary:
+      - administrative
+      border_status:
+      - dispute
+      boundary_type:
+      - maritime