T and F commands: continuation of #1450

[mbertucci47]

Brief outline of the enhancement

This is simply a continuation of #1450 since that issue was closed after PR #1504 without a decision on whether the following 2e TF commands need separate T and F versions.

\IfDocumentMetadataTF 
\IfExplAtLeastTF 
\IfFontSeriesContextTF 
\IfPDFManagementActiveTF

This issue is not a request for these commands, just a check to make sure @muzimuzhi's issue does not get lost.