feat: App API v2 (#10077)

# Which Problems Are Solved

This PR *partially* addresses #9450 . Specifically, it implements the
resource based API for the apps. APIs for app keys ARE not part of this
PR.

# How the Problems Are Solved

- `CreateApplication`, `PatchApplication` (update) and
`RegenerateClientSecret` endpoints are now unique for all app types:
API, SAML and OIDC apps.
  - All new endpoints have integration tests
  - All new endpoints are using permission checks V2

# Additional Changes

- The `ListApplications` endpoint allows to do sorting (see protobuf for
details) and filtering by app type (see protobuf).
- SAML and OIDC update endpoint can now receive requests for partial
updates

# Additional Context

Partially addresses #9450

pkg/grpc/app/v2beta/application.go

@@ -0,0 +1,5 @@
+package app
+
+type ApplicationConfig = isApplication_Config
+
+type MetaType = isUpdateSAMLApplicationConfigurationRequest_Metadata