tapis support for run2, and support for using the menu from a pool file with the menu in metadata

Adds support for tapis with run2 GRLs. @stelzer should confirm that the modification to TrigConfFrontier.py is acceptable.

Also adds support for passing a pool file, then the menu will be taken from the file's metadata (assumes it has the menu in the metadata).

Note this will give a slight behaviour change to the old API, in that if the flags container has input files, that will be used as a priority over the triggerMenuSetup flag to setup the release's menu versions. so don't set the input files if you want the old behaviour.