## Context
View tables were missing some FK, we are also introducing delete cascade
on those tables when needed to leverage pg cascade deletion instead of
having to implement it.
Also renaming those classes with Entity suffix to follow repo
guidelines.
Created:
- Services
- Resolvers
- Controllers
- Tests for services
- Integration tests for GraphQL and Rest
Updated the Rest API playground
Added new feature flag `IS_CORE_VIEW_ENABLED`
Updated `viewFilter` `operand` and `view` `type` to be enums rather than
strings and generated migration file.
Closes https://github.com/twentyhq/core-team-issues/issues/1259
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Co-authored-by: Félix Malfait <felix.malfait@gmail.com>
Co-authored-by: Charles Bochet <charles@twenty.com>
