Intellisense: list tables in default schema if there is no schema in scope

[isc-tleavitt]

If there is no schema in scope, completions for tables in the default schema should be offered.

(from discussion in #31 )

[isc-tleavitt]

@bdeboe neither %SYSTEM.SQL:DefaultSchema nor %SYSTEM.SQL.Schema:Default is not flagged as SQLProc. Thoughts on sqltools-intersystems-driver creating a function for its own use?

[bdeboe]

they are SqlProcs, I ran that query before I suggested it :-)
it's the online class ref that's not making this visible (yet the local one does).

[isc-tleavitt]

@bdeboe they're first SqlProcs in 2022.3.0 ;)

[bdeboe]

oops, I thought that was part of the 2020-era cleanup of our SQL utilities