Add before (pre-) and after (pos-) sql script objects

More detailed version of feature request: "2799: Add before (pre-) and after (pos-) sql scripts"

Add 'pre-script' and 'post-script' text objects so it's possible to write SQL that should be inclued before and after the database generated SQL script file. The text objects would have a Name (showed in a list), a Text (free SQL script) and an Order (possibility to be ordered on the list).

Text objects could be used to describe any non-supported by Data Modeler or very specific database objects, example:

Add pre-script text object named 'Db Exceptions', with Text (script):

create exception Ex_error1 'My exception 1';
create exception Ex_error2 'My exception 2';

Add pre-script text object named 'Special Domain', with Text (script):

create domain NOT_SUPORTED_IN_DOMAIN_EDITOR special-type-info;

Add post-script text object named 'ConnectTrigger', with Text (script):

Set term ^;
create database trigger ConnectTrigger on CONNECT as
begin
/* some code */
end^
Set term ;^

Add post-script text object named 'SecurityGrants', with Text (script):

create role Abc;
grant all on table Table1 to role Abc;
grant select on table Table2 to role Abc;

And so on...