Feature/154 update do files estimating mental health and wellbeing

[andrewbaxter439]

What

• adds do files for estimating mental health and wellbeing effects from initial populations
• updating regression files from these do files
• updates statistics to align with these

Why

• These do files were missing and results not reproducible

[andrewbaxter439]

Have highlighted some team as potential reviewers, but for hopefully straightforward questions:

• @dav-sonn these commits by and large only touch do files with only one interaction with java files. Statistics outputs are the only place I think where things may conflict with refactoring. Can hold off merging and redo these files after if useful?
• @dariaple and @ANBurdett - I've modelled my do files on the previous ones and aimed to follow their excellently helpful structure! They work and produce valid results. Any issues/tips welcome
• Also @ANBurdett I think: I have kept these producing validation data as per other do scripts, but haven't attempted post/pre-estimate validation graphs yet! This is a bit beyond what I can achieve in the near future. If it's worth doing, and potentially more efficiently done by a seasoned Stata user, would it be useful discussing this as next steps?