support parameters in mssql EXECUTE stored procedure calls

[lovasoa]

Initially reported in SQLPage as sqlpage/SQLPage#655

Currently, sqlparser supports stored procedure calls with

EXECUTE MyProcedure;

However, the Microsoft SQL Server syntax does support passing parameters to stored procedures with a simple whitespace between the procedure name and arguments:

EXECUTE MyProcedure 'argument 1', 'argument 2';

It also supports named arguments

EXECUTE MyProcedure @my_first_arg = 'argument 1', @my_second_arg = 'argument 2';

reference: https://learn.microsoft.com/en-us/sql/relational-databases/stored-procedures/execute-a-stored-procedure?view=sql-server-ver16

Related, but different issues:

• Support mssql exec #1275
• Support schema qualified stored procedures for mssql #1276