Implement command "query proposals"

[smelc]

Changelog

- description: |
    Implement the `query proposals` command
# 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

Fixes #903

How to trust this PR

Tested with cardano-testnet: https://github.com/IntersectMBO/cardano-node/commits/smelc/test-query-proposals/

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

[palas]

Looks good. I cannot find any issues by looking at the code.

It would be good to also test:

• Querying for more than one governance action ids at the same time
• Query using the --all-proposals flag
• Checking the result is the same as for cardano-cli conway query gov-state | jq .proposals as in the acceptance criteria.

I've also noticed that it is not clear in the documentation generated that you can actually query for several action ids. But I've checked and it is done the same as for other commands, so this PR is fine.

[smelc]

Querying for more than one governance action ids at the same time
Query using the --all-proposals flag
Checking the result is the same as for cardano-cli conway query gov-state | jq .proposals as in the #903.

@palas> Yep we actually did all of this manually with @CarlosLopezDeLara in cardano-testnet 👌