feat: show relations of nested places in Place detail page

[gythaogg]

This pull request introduces several changes to the apis_ontology module, primarily focusing on adding new columns and templates for handling place relations, as well as extending existing templates and tags to support nested relations.

Key changes include:

New Columns and Templates:

• Added RelationSubjectColumn class to apis_ontology/tables.py for displaying subjects in the relations table.
• Created new template relation_subject.html to render subject links in the relations table.

New Table Class:

• Introduced PlaceRelationsTable class in apis_ontology/tables.py to handle place-specific relations with a defined field order.

Template Modifications:

• Updated place_detail.html and place_form.html to include the new place_list_relations_include_tabs.html template instead of the generic list_relations_include_tabs.html. [1] [2]
• Added place_list_relations_include_tabs.html template to extend the base relations template and load nested relations.

New Template Tag:

• Added relations_from_place template tag in nested_relations.py to fetch relations, including nested locations within a place.

closes #49