Add postgis extension - a spatial database extender for PostgreSQL

[tomas-stefano]

Context

This PR adds the postgis extension to Publish/Find.

The postgis adapter does not support Rails 8 at the moment: rgeo/activerecord-postgis-adapter#411 (comment)

So using the extension in it's raw mode.

I’ve encountered issues with the internal tables PostGIS uses for geospatial calculations when recreating the database.

Running the usual setup commands:

rails db:drop db:create db:schema:load db:migrate

leads to this error:

PG::DependentObjectsStillExist: ERROR:  cannot drop table spatial_ref_sys because extension postgis requires it

To work around this, I added the following initializer to ignore spatial_ref_sys during schema dumps:

ActiveRecord::SchemaDumper.ignore_tables |= ["spatial_ref_sys"]

Guidance to review

1. Does it work on the review app?
   • Run in the review db: SELECT postgis_full_version(); (e.g ActiveRecord::Base.connection.execute("SELECT postgis_full_version();").values)
   • run SELECT * FROM spatial_ref_sys LIMIT 10;
   • run SELECT * FROM geometry_columns LIMIT 10;
2. Does terraform includes postgis?

[RMcVelia]

terraform change looks good