Performance improvements for SSMS query while trying to expand stored…

… procedures (#1956)

Currently, the SSMS query to expand stored procedures is found to be very slow (~ 6 hours for 1000 procedures).
The bad performance is found to be majorly occuring from sys.all_objects view. So, the following modifications have been done to the sys.all_objects :

Bad row estimation arising due to the is_ms_shipped column in sys.all_objects view. This change fixes it by pushing down the computation of is_ms_shipped column to the respective unions.
Made the datatype of type and name column consistent and removed the outer CAST as we are already casting them in the respective UNIONs.
Removed subqueries and replaced them with suitable JOINs for better query planning.

Issues Resolved
BABEL-4008

Signed-off-by: Sai Rohan Basa [email protected]