[Epic] - Prepare exposure-lib for the 25.01 release

To prepare exposure-lib for the 25.01 release, the following issues need to be addressed:

• Create an empty branch v25.01.
• Create empty files abstract.py, spatialite.py and postgis.py to split the codes formerly in database.py (#169 (closed))
• Prepare exposure-lib for entity-initializer:
  • Implement the handling of schema/table names for SpatiaLiteExposure and PostGISExposure (#169 (closed)).
  • Implement function get_reference_features_in_geometry() (https://git.gfz-potsdam.de/globaldynamicexposure/development-code/-/blame/entity-initializer/refactor/entityinitializer/pseudocode.py?ref_type=heads#L16).
  • Implement function get_tiles_from_geometry() (#167).
  • Implement function get_tile_entity_id() (#167).
  • Implement function get_sum_built_area_in_geometry() (https://git.gfz-potsdam.de/globaldynamicexposure/development-code/-/blame/entity-initializer/refactor/entityinitializer/pseudocode.py?ref_type=heads#L57).
  • Implement function insert_reference_tile() (#167).
  • Implement function get_source_id() (https://git.gfz-potsdam.de/globaldynamicexposure/development-code/-/blame/entity-initializer/refactor/entityinitializer/pseudocode.py?ref_type=heads#L86).
  • Implement function get_country_boundary_geometry() (already implemented; just copy)
• Prepare exposure-lib for exposure-initializer:
  • Implement the create_tables() function for SpatiaLiteExposure (#170)
• Implement unit and acceptance tests:
  • Create an empty PostGIS database using GitLab-CI (#168 (closed)).

To start creating the 25.01 model:

• Create beta version

\rfc @laurens @pdlmora @tara @gislars @tara