Renamed TALLY to GOV

[Soupstraw]

Description

This PR applies the following substitutions:

s/Tally/Gov/g
s/VDel/GovCert/g

I also renamed

eras/conway/impl/src/Cardano/Ledger/Conway/Rules/Tally.hs -> Gov.hs
eras/conway/impl/src/Cardano/Ledger/Conway/Rules/VDel.hs -> GovCert.hs

.. and updated the Conway cabal file with the new paths.

resolves #3515
resolves #3505

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

[lehins]

Looks good, but still needs a little work

[lehins]

Just some versioning stuff, otherwise looks great

[lehins]

Looks great. Just need a rebase on master and one comment from Teodora

[teodanciu]

@Soupstraw Not sure if you've seen that there is a little compilation error probably after some renamings? Just mentioning because I see you've enabled automerge, so not sure if you're aware of the problem