Consider grouping related arguments into modules

[jamesmbaazam]

There is an opportunity to group related arguments into a single module like has been done in EpiNow2.

The benefit of this is that, users can see all controls in one place rather than scrolling through individual arguments, which risks them missing some of them. You also then have a lot of control over testing each module by assigning them a class, testing the arguments, etc.

The downside of implementing this is that you will have to deprecate/overhaul a major part of the current interface but that can be done through a series of soft deprecations, forewarning the users.

This is probably better done now than later as the package gains users through trainings being run.

Concretely, I suggest to:

• add foi argument to injest and process "is_log_foi", "foi_prior", "foi_sigma_rw" , "foi_index", "foi_init", and
• add seroreversion argument to injest and process "is_seroreversion" and "seroreversion_prior".

With this, you can remove the prefixes such as "foi" and "seroreversion" from the the current argument names.