feat(api): add OIDC session service (#6157)

This PR starts the OIDC implementation for the API V2 including the Implicit and Code Flow.


Co-authored-by: Livio Spring <[email protected]>
Co-authored-by: Tim Möhlmann <[email protected]>
Co-authored-by: Stefan Benz <[email protected]>

internal/query/embed/auth_request_by_id.sql

@@ -0,0 +1,15 @@
+select
+    id,
+    creation_date,
+    login_client,
+    client_id,
+    scope,
+    redirect_uri,
+    prompt,
+    ui_locales,
+    login_hint,
+    max_age,
+    hint_user_id
+from projections.auth_requests %s
+where id = $1 and instance_id = $2
+limit 1;