Improve native script handling

[lehins]

Description

• Remove redundant script hash verification. Script Hashes are not transmitted over the wire, they are computed upon deserialization. This means there is no point in recomputing and verifying those hashes as a predicate check in the rules
• Short circuit multisig and timelock verification for RequireMOf as soon as necessary number of scripts have been validated. Previously it was validating all scripts, regardless of how many was needed.
• Remove the whole Phased distinction, since it was not used nor is it needed for phase2 scripts. It was only necessary for native, phase1 scripts. That is why a simpler interface was added that deals with native scripts only. Addition of NativeScript, getNativeScript and validateNativeScript

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

[TimSheard]

Seems like a better approach. using 'go' seems a bit too obtuse though.