[IMP] sql_export: black, isort, prettier

sql_export/readme/ROADMAP.md

@@ -0,0 +1,16 @@
+- Some words are prohibited and can't be used is the query in anyways,
+  even in a select query:
+  - delete
+  - drop
+  - insert
+  - alter
+  - truncate
+  - execute
+  - create
+  - update
+
+See sql_request_abstract module to fix this issue.
+
+- checking SQL request by execution and rollback is disabled in this
+  module since variables features has been introduced. This can be fixed
+  by overloading \_prepare_request_check_execution() function.