[pgAdmin4][Patch]: RM #3446 plpgsql keyword should displayed in SQL pane for EPAS-11

Hi Hackers,

Attached is the patch to fix the RM #3446 "plpgsql keyword should displayed
in SQL pane for EPAS-11". While fixing it, I have found below issues in
function/procedure:

1. Procedures for EPAS 11 always created as 'edbspl', even though
language is sql or plpgsql.
2. Not able to create Function/Procedure/Trigger function if the
language is "*C*" for all supported database server.
3. Function creation for EPAS 9.6 and above when set "Window?" flag to
"Yes".
4. Disable Volatility, Strict, Parallel, Estimated cost and Leak prof
while creating procedures in EPAS 11 when language is not 'edbspl'.
5. Rename "default" folder to "11_plus" inside "*pg*" directory for
procedures, as procedures are supported from PG11 onwards.
6. Creating/Deleting parameter in Procedure for PG 11.
7. Drop procedures with arguments for PG/EPAS 11.
8. pg_proc table has added default value 'v' for Volatility, 100 for
Cost and 'u' for Parallel for any language. All the three are not supported
for Procedures in PG/EPAS 11 (excluding 'edbspl' language for EPAS).
Fixed the issue where it is visible in properties panel if we create
procedure using language 'plpgsql' or 'sql'.

Attached patch contains the fix for all the above issues. Please review it.

--
*Akshay Joshi*

*Sr. Software Architect *

*Phone: +91 20-3058-9517Mobile: +91 976-788-8246*