Context

In the way to !4502 (merged), this follows !4692 (merged).

The type ty is enriched with a new parameter which is a dependent boolean representing whether the type is comparable or not.

What matters is that the type ty is correctly defined. Afterwards it won't be possible to get this witness wrong.

comparable_ty and ty are not united yet.

Manually testing the MR

🐫

~~[ ] Document the interface of any function added or modified (see the coding guidelines)~~
~~[ ] Document any change to the user interface, including configuration parameters (see node configuration)~~
Provide automatic testing (see the testing guide).
[ ] For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else). (will do at the end)
Select suitable reviewers using the Reviewers field below.
Select as Assignee the next person who should take action on that MR