Introduce pots/v0 namespace for canonical state

[qnikst]

Description

Checklist

• Commits in meaningful sequence and with useful messages.
• Tests added or updated when needed.
• CHANGELOG.md files updated for packages with externally visible changes.
  NOTE: New section is never added with the code changes. (See RELEASING.md).
• Versions updated in .cabal and CHANGELOG.md files when necessary, according to the
  versioning process.
• Version bounds in .cabal files updated when necessary.
  NOTE: If bounds change in a cabal file, that package itself must have a version increase. (See RELEASING.md).
• Code formatted (use scripts/fourmolize.sh).
• Cabal files formatted (use scripts/cabal-format.sh).
• CDDL files are up to date (use scripts/gen-cddl.sh)
• hie.yaml updated (use scripts/gen-hie.sh).
• Self-reviewed the diff.

[qnikst]

This PR is based on top of the #5548 and is intended to be merged and reviewed after that one

[qnikst]

I've prepared a commit for the next namespace, interesting and discussible thing here is introducing CanonicalCoin and type class for conversion. This is related to the conversation about integer conversion happened on the meeting 2026-02-02, whether a library should be used to make it safe. Theoretically it's unsafe to convert from CanonicalCoin Integer to CompactCoin that is 64bit size.

I could adopt the code to the approach chosen by the project.