Tile duplicate housenumber filtering (#1391)

This PR introduces simple filtering of duplicate housenumbers.

Simple means that filtering is done withing the tile.
Duplicates are defined as same housenumber, street, block_number[1].

Duplicates are usually caused by POIs. People like to add addresses to them. Most POIs have names so to prioritize addresses we pick features without names first.

Formula is: `row_number() OVER(PARTITION BY concat(street, block_number, housenumber) ORDER BY has_name ASC) == 1`

layers/housenumber/housenumber.yaml

@@ -3,6 +3,7 @@ layer:
   description: |
       Everything in OpenStreetMap which contains a `addr:housenumber` tag useful for labelling housenumbers on a map.
       This adds significant size to *z14*. For buildings the centroid of the building is used as housenumber.
+      Duplicates within a tile are dropped if they have the same street/block_number (records without name tag are prioritized for preservation).
   buffer_size: 8
   srs: +proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over
   fields: