This PR updating Natural Earth dataset from v4.1 to 5.1.2. It is in cooperation with https://github.com/openmaptiles/openmaptiles-tools/pull/414, where is `import-data` docker image updated. PR removes manual fixes for lake merging (already fixed in version 5.1.2) Switched comparison from `gn_ascii` (removed from NE5) to `name_en`. Could be merged after https://github.com/openmaptiles/openmaptiles-tools/pull/413. After OMT-T is merged, it will use `latest` image (until the release of OMT-T v7)