LimitToGlobal brings in Ticket CFs

From the LimitToGlobal docs

    Note that this will cause the collection to only return ticket CFs.

That isn't really true, since LimitToLookupType('RT::Queue-RT::Ticket');
gets ORed together with LimitToLookupType(RT::Asset->CustomFieldLookupType );
in LimitToCatalog, so you got global Asset and global Ticket CFs on your
assets search.

We force a limit to Object 0 which is global.  Core LimitToGlobal should
probably stop specifying a LookupType.
Include global cfs in the TSV, as well as Basics and People boxes

In all these locations, we were only getting CFs applied to this
catalog.  Use the same fix from 731b90d2 to also include global Assets
CFs.

Fixes issues #30249
Update documentation which misleads about LimitToGlobal
Merge branch 'global-custom-fields'