Remove check for DRep metadata size

[CarlosLopezDeLara]

Changelog

- description: |
    https://cips.cardano.org/cip/CIP-0119 proposes using a schema where the basic jsonld structure is heavier than 512. The agreement is that DBsync will set a limit for the size of metadata that is downloaded into the DB, but API or CLI do not need to impose any restrictions.
# 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
  # - refactoring    # QoL changes
  # - 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

https://cips.cardano.org/cip/CIP-0119 proposes using a schema where the basic jsonld structure is heavier than 512.
cardano-foundation/CIPs#835

How to trust this PR

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Checklist

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