ref(control_silo): Move Identitiy model to users module

[Christinarlong]

Part of moving control silo user related resources into the users module. Includes adding import shim for any getsentry refs. Also adds minor typing to some identity functions (will point out).

Apart of (#73856)

[Christinarlong]

I interpreted the get() function returning a cls("Identity") which would just be an Identity class... (???)

[markstory]

Wouldn't this be IdentityProvider. The get() will return an instance of the registered types (Providers) based on the string name provided.

Providers are registered here

sentry/src/sentry/identity/__init__.py

Lines 25 to 34 in 4fb67fb

	register(SlackIdentityProvider) # NOQA
	register(GitHubIdentityProvider) # NOQA
	register(GitHubEnterpriseIdentityProvider) # NOQA
	register(VSTSIdentityProvider) # NOQA
	register(VstsExtensionIdentityProvider) # NOQA
	register(VercelIdentityProvider) # NOQA
	register(BitbucketIdentityProvider) # NOQA
	register(GitlabIdentityProvider) # NOQA
	register(GoogleIdentityProvider) # NOQA
	register(DiscordIdentityProvider) # NOQA

The Slack provider is found

sentry/src/sentry/identity/slack/provider.py

Line 5 in 6ef9112

class SlackIdentityProvider(OAuth2Provider):

and the class tree for those ends in Provider

sentry/src/sentry/identity/base.py

Line 7 in 6ef9112

class Provider(PipelineProvider, abc.ABC):

[Christinarlong]

Ohhhh, gotchas. I completely missed the whole provider registration and that the self.values in IdentityManager was populated with Providers from the registration. 🫠 Thank yous for the class by class explanation!