feat: update user secrets queries for REST API and injection (#23998)

Update queries as prep work for user secrets API development:
- Switch all lookups and mutations from ID-based to user_id + name
- Split list query into metadata-only (for API responses) and
with-values (for provisioner/agent)
- Add partial update support using CASE WHEN pattern for write-only
value fields
- Include value_key_id in create for dbcrypt encryption support
- Update dbauthz wrappers and remove stale methods from dbmetrics

coderd/database/dbgen/dbgen.go

@@ -1597,6 +1597,7 @@ func UserSecret(t testing.TB, db database.Store, seed database.UserSecret) datab
 		Name:        takeFirst(seed.Name, "secret-name"),
 		Description: takeFirst(seed.Description, "secret description"),
 		Value:       takeFirst(seed.Value, "secret value"),
+		ValueKeyID:  seed.ValueKeyID,
 		EnvName:     takeFirst(seed.EnvName, "SECRET_ENV_NAME"),
 		FilePath:    takeFirst(seed.FilePath, "~/secret/file/path"),
 	})