Change environment for ShelleyPOOLREAP rule

[lehins]

Description

Previous type for environment was PParams, which was unused. Current environment is set to VState, because it will be needed for correct implemention of obligationCertState used in the rule's assertion. It will be needed for DRep deposits: #3645

Also rename CDDL Committee certificates variables:

• reg_committee_hot_key_cert -> auth_committee_hot_cert
• unreg_committee_hot_key_cert -> resign_committee_cold_cert

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated
• 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)
• 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)
• Code is formatted with fourmolu (use scripts/fourmolize.sh)
• Cabal files are formatted (use scripts/cabal-format.sh)
• hie.yaml has been updated (use scripts/gen-hie.sh)
• Self-reviewed the diff

[Soupstraw]

LGTM, thanks for adding the VState!