Vetoes in PyGRB efficiency and page_tables scripts

[pannarale]

This PR is the tenth in the series started in PR #4929. Much like PRs #4947, #4950, #4955, and #4958, this PR provides versions of pycbc_pygrb_efficiency and pycbc_pygrb_page_tables that use veto and segments files, as well as the utilities introduced recently to streamline the PyGRB results scripts.

This PR also fixes a bug with the index used to look up template chirp masses (around line 406 of pycbc_pygrb_page_tables).

I reccomend looking at this after https://github.com/gwastro/pycbc/pull/4977/files, because the background generation is similar.

Standard information about the request (and the following ones that will be linked to this)

This is a: a new feature enabling veto definer file usage in PyGRB. Utilities and scripts in results production are being streamlined along the way.

This change affects: PyGRB

This change changes: result presentation / plotting and scientific output.

Motivation

Now that the workflow generator passes the veto definer file to the jobs where needed, its usage in the PyGRB results scripts is possible.

Testing performed

The totality of the changes that will be broken down in multiple PRs was tested on GRB 170817A data by producing a full results webpage (see here).

• The author of this pull request confirms they will adhere to the code of conduct

[pannarale]

@Thomas-JACQUOT, the commit above is the fix to the issue you found in your 2IFO run and raised with @sebastiangomezlopez ebastian.
Would you mind checking if it fixes your run? You would have to

1. copy page_tables locally from the environment you used
2. run it from command line and reproduce the error you are seeing
3. apply the same one line fix given here and
4. run again.

If you have difficulties finding the command line to run, just let me know.

[titodalcanton]

No more comments from me.