Simplify Name Templates regexp with custom keywords or a convenience buttons for common use cases

[JoeZiminski]

Currently the Name Templates feature that allows definition of custom templates to validate against uses straight regexp syntax.

e.g. sub-\d\d\d_id-.?.?.?.?.?.?_date-.*

which is obviously pretty confusing.

Two options are

1. to add in custom tags that are clearer. However it may be hard to tell intended text vs non-intended text (e.g. we use D for digit, but what is a D is actually in the name).
2. Probably easier is in the TUI to have convenience buttons like 'Any Digit' that can be pressed to automatically fill in the template with \d. This makes it easy to make templates in the TUI as well as teach the regexp syntax.