Expand on STM Bytes test

[jmid]

This is the extension of the STM Bytes test mentioned in #546.
It targets 5 more bindings from the Bytes module - a decent increase over the existing 7.
I lost momentum when I hit the many index/contains/is_valid bindings covered by src/bytes/lin_tests.ml... 😬

While writing this, I noticed that Util.Pp only covers up to cst3 - and similarly for QCheck.Gen.map{,2,3}.
I think it would be a good idea to extend both to cover up to {cst,map}5. 🙂 Edit: fixed - see below

[jmid]

While writing this, I noticed that Util.Pp only covers up to cst3 - and similarly for QCheck.Gen.map{,2,3}. I think it would be a good idea to extend both to cover up to {cst,map}5. 🙂

• I've now released qcheck-core.0.25 containing QCheck.Gen.map{,4,5} and therefore bumped the lower bound to that, and removed the temporary map4 definition again
• I've also added Util.Pp.cst5 for uniformity and a CHANGES entry for that and cst4
• Finally I've rebased the PR on main, reordered and cleaned up the commits

[jmid]

CI summary: all 36 workflows passed

[jmid]

CI summary for merge to main: all 37 workflows passed
(an MSVC workflow failed its net connection and needed rerunning though)