1) From PG 15 onward, the datlastsysoid has been removed from the table pg_database.
We have added the constant _DATABASE_LAST_SYSTEM_OID = 16383, all the objects below
this value are considered to be system objects. Modified the pgAdmin logic accordingly.
2) Concatenation operator '||' needs a specific typecast to be applied to query variables. Modified SQL's accordingly.
Fixes#7283
* Hide the security tab for the objects under the catalog schema.
Patched by Surinder Kumar, vastly improved by me.
* Make the securtiy label across all the nodes, using the same backbone
model across the nodes, and make changes in the backend code for the
same.
