fix: join tables from another schema with main schema tables (#917)

(cherry picked from commit 1860c57)

Author: nextchamp-saqib

insights/insights/doctype/insights_data_source_v3/insights_data_source_v3.py

@@ -408,6 +408,8 @@ def get_ibis_table(self, table_name):
         if self.database_type == "PostgreSQL" and "." in table_name:
             schema, table = table_name.split(".")
             return remote_db.table(table, database=schema)
+        if self.type == "REST API":
+            return remote_db.table(table_name, database=self.schema)
         return remote_db.table(table_name)