Lift TotalPeriodsKES to the type level in KESAlgorithm

[dancewithheart]

Description

Fixes #364

This PR lifts the total number of supported KES periods to the type level by
adding:

type TotalPeriodsKES v :: Nat

to KESAlgorithm.

This is a small API change for downstream KESAlgorithm instances.

Changes

• add TotalPeriodsKES as an associated type of KESAlgorithm
• require KnownNat (TotalPeriodsKES v) in the KESAlgorithm superclass context
• make totalPeriodsKES a default term-level reflection of TotalPeriodsKES
• update KES instances to define TotalPeriodsKES at the type level
• adjust affected instance contexts using generic KES CBOR helpers
• add a test checking that totalPeriodsKES agrees with TotalPeriodsKES

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated
• All visible changes are prepended to the latest section of a CHANGELOG.md for the affected packages.
  New section is never added with the code changes. (See RELEASING.md)
• When applicable, versions are updated in .cabal and CHANGELOG.md files according to the
  versioning process.
• The version bounds in .cabal files for all affected packages are updated.
  If you change the bounds in a cabal file, that package itself must have a version increase. (See RELEASING.md)
• Self-reviewed the diff