refactor replCfg to look more like plugins/plugin config (#91142)

* refactor replCfg to look more like plugins/plugin config
* validateReplicaConfigs must handle inconsistencies in type names due to the WithHooks suffix

pkg/services/sqlstore/database_config_test.go

@@ -237,6 +237,22 @@ func TestValidateReplicaConfigs(t *testing.T) {
 		require.NoError(t, err)
 	})
 
+	t.Run("valid but awkward config", func(t *testing.T) {
+		inicfg, err := ini.Load([]byte(testReplCfg))
+		require.NoError(t, err)
+		cfg, err := setting.NewCfgFromINIFile(inicfg)
+		require.NoError(t, err)
+
+		dbCfgs, err := NewRODatabaseConfigs(cfg, nil)
+		require.NoError(t, err)
+
+		// The primary is mysql, but the replicas are mysqlWithHooks. This can
+		// occur when some but not all the replicas (or primary) have
+		// instrument_queries enabled
+		err = validateReplicaConfigs(&DatabaseConfig{Type: "mysqlWithHooks"}, dbCfgs)
+		require.NoError(t, err)
+	})
+
 	t.Run("invalid config: primary database type mismatch", func(t *testing.T) {
 		// valid repl config, the issue is that the primary has a different type
 		inicfg, err := ini.Load([]byte(testReplCfg))
@@ -284,9 +300,15 @@ name = grafana
 user = grafana
 password = password
 host = 127.0.0.1:3306
-[database_replicas.one] =
+[database_replica.one]
+name = grafana
+user = grafana
+password = password
 type = mysql
 host = 127.0.0.1:3306
-[database_replicas.two] =
+[database_replica.two]
+name = grafana
+user = grafana
+password = password
 type = postgres
 host = 127.0.0.1:3308`