shareable workspaces pt. 2

[alex-mcgovern]

Second part of #1067 — this adds a new endpoint GET /api/v1/workspaces/:workspace_name that returns a full workspace config.

With this we have the prerequisites for a upload/download flow on a per-workspace basis.

These changes are integrated into the frontend in this PR: stacklok/codegate-ui#379

• adds provider_endpoint_name and provider_endpoint_type to the muxes table
• changes MuxRule model used by the API to include provider_type and
  provider_name and removes provider_id
• creates a new MuxRuleWithProviderId model used internally for transporting
  mux rules
• all endpoints that interact with provider endpoints have been updated so that
  they don't require knowledge of the provider ID
• GET /api/v1/workspaces/:provider_id was already in use for listing providers in use by a workspace, but after speaking with @JAORMX we decided to move this elsewhere. You can achieve the same thing with GET /api/v1/workspaces?provider_name={ID} now instead
• there are a number of other breaking changes impacting the UI, but these are
  dealt with in a separate PR

[JAORMX]

The main thing is the db schema changes

[lukehinds]

Overall lgtm , do we need a db migration for the changes to db/models?

[alex-mcgovern]

Overall lgtm , do we need a db migration for the changes to db/models?

There were DB schema changes in a previous iteration, but we decided they were unnecessary, the only change to a DB model is this one:

class ProviderModel(BaseModel):
    provider_endpoint_id: str
+   provider_endpoint_type: str
    provider_endpoint_name: Optional[str] = None
    name: str

Which is populated via a JOIN — it's not the cleanest, but "it works"™️