Constrain the size of leios_certificate signers

[ch1bo]

The maximum length is determined by the maximum LeiosVoterId. As this is a Word16, the max number of entries is 65535 bits = 8192 bytes

Done as a separate PR to #5872, so it does not block that from merging.

TODO: This needs, either:

• Check size in the decodeLeiosCert in cardano-crypto-leios and release as a 0.1.1 or even 0.2
• Deprecate and move en-/decoders to a ledger package
  • Deprecate decodeLeiosCert in cardano-crypto-leios now and remove in a later 0.2
  • Add encodeLeiosCert/decodeLeiosCert that are size constrained and also support indefinite length bytes using cardano-ledger-binary

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.