Move renderSafeHashAsHex from cardano-node

[smelc]

Changelog

- description: |
    Add renderSafeHashAsHex, which we want to remove from cardano-node and use in cardano-cli
# uncomment types applicable to the change:
  type:
   - feature        # introduces a new feature
  # - breaking       # the API has changed in a breaking way
   - compatible     # the API has changed but is non-breaking
  # - optimisation   # measurable performance improvements
  # - improvement    # QoL changes e.g. refactoring
  # - bugfix         # fixes a defect
  # - test           # fixes/modifies tests
  # - maintenance    # not directly related to the code
  # - release        # related to a new release preparation
  # - documentation  # change in code docs, haddocks...

Context

We're using this function in two places:

1. https://github.com/IntersectMBO/cardano-node/blob/76ef0fe7cd716426e41813958569521dd80cda8b/cardano-testnet/test/cardano-testnet-test/Cardano/Testnet/Test/LedgerEvents/Gov/ProposeNewConstitution.hs#L415
2. https://github.com/input-output-hk/cardano-cli/blob/694782210c6d73a1b5151400214ef691f6f3ecb0/cardano-cli/src/Cardano/CLI/EraBased/Run/Governance/Hash.hs#L67

but this function is better placed here, and reused from these existing callers.

How to trust this PR

This PR moves code around repos

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• NA New tests are added if needed and existing tests are updated. See Running tests for more details
• Self-reviewed the diff

[Jimbo4350]

👌

[smelc]

Will be merged after #411 lands