[IMP] Energy Communities API Base Structure

This MR defines the basic structure for the API on energy_communities. Next endpoints will be based on the ones introduced here.

• Migrated from FastAPI strategy to BaseRest
• Testing strategy defined and working
• Introducing components to obtain all necessary API Info
• Input and output validation using Pydantic
• Model mapping using Pydantic
• Fixed demo data (after the fix it broke again)
• Introduced correct user_id and company_id on context
• API-KEY and JWT authentication available
• Exceptions returned as json (instead html)
• Review of ACL and record rules in order to be compatible with the API
• Introducing new API provider Role in order to restrict external users to model data
• /energy-communities/me and /energy-communities/me/communities endpoints available
• /energy-selfconsumption/projects and /energy-selfconsumption/projects/<project_code> and /energy-selfconsumption/projects/<project_code>/members available

Impacted tasks:

• OP#138
• OP#312
• OP#318
• OP#385