Rename private functions

Rename __cdb_* "private" functions to __ft_*, kind of a namespace to
avoid name clashing.

scripts-available/CDB_PG_Federated_Tables.sql

@@ -4,7 +4,7 @@
 
 -- Take a config jsonb and transform it to an input suitable for
 -- _CDB_SetUp_User_PG_FDW_Server
-CREATE OR REPLACE FUNCTION @extschema@.__cdb_credentials_to_user_mapping(input_config jsonb)
+CREATE OR REPLACE FUNCTION @extschema@.__ft_credentials_to_user_mapping(input_config jsonb)
 RETURNS jsonb
 AS $$
 DECLARE
@@ -24,7 +24,7 @@ LANGUAGE PLPGSQL IMMUTABLE PARALLEL SAFE;
 
 -- Take a config jsonb as input and return it augmented with default
 -- options
-CREATE OR REPLACE FUNCTION @extschema@.__cdb_add_default_options(input_config jsonb)
+CREATE OR REPLACE FUNCTION @extschema@.__ft_add_default_options(input_config jsonb)
 RETURNS jsonb
 AS $$
 DECLARE
@@ -63,8 +63,8 @@ AS $$
 DECLARE
     final_config jsonb;
 BEGIN
-    final_config := @extschema@.__cdb_credentials_to_user_mapping(
-        @extschema@.__cdb_add_default_options(server_config)
+    final_config := @extschema@.__ft_credentials_to_user_mapping(
+        @extschema@.__ft_add_default_options(server_config)
     );
     PERFORM cartodb._CDB_SetUp_User_PG_FDW_Server(server_alias, final_config::json);
 END

test/extension/test.sh

@@ -690,7 +690,7 @@ function test_federated_tables() {
 }
 EOF
 
-    # Unit-test __cdb_credentials_to_user_mapping
+    # Unit-test __ft_credentials_to_user_mapping
     read -d '' expected_user_mapping <<- EOF
 {
     "server": {
@@ -704,10 +704,10 @@ EOF
     }
 }
 EOF
-    sql postgres "SELECT cartodb.__cdb_credentials_to_user_mapping('$federated_server_config') = '$expected_user_mapping'" \
+    sql postgres "SELECT cartodb.__ft_credentials_to_user_mapping('$federated_server_config') = '$expected_user_mapping'" \
         should 't'
 
-    # Unit-test __cdb_add_default_options
+    # Unit-test __ft_add_default_options
     read -d '' expected_default_options <<- EOF
 {
     "server": {
@@ -725,7 +725,7 @@ EOF
     }
 }
 EOF
-    sql postgres "SELECT cartodb.__cdb_add_default_options('$federated_server_config') = '$expected_default_options'" \
+    sql postgres "SELECT cartodb.__ft_add_default_options('$federated_server_config') = '$expected_default_options'" \
         should 't'
 
     # There must be a function with the expected interface