wallet: deprecate feeRate in fundrawtransaction/walletcreatefundedpsbt #20483

Continuing work on #19543 and following the plan outlined in #20484 (comment), deprecate the feeRate option in fundrawtransaction and walletcreatefundedpsbt to avoid confusion with fee_rate, as the two options have different units (BTC/kvB and sat/vB) and similar spellings.

This PR currently targets deprecation for 0.21 and so no release notes are added here, as the wiki would be edited instead. Will update if tagged for 0.22 instead.

The last commit, "test: add feeRate tests to rpc_deprecate.py," is best reviewed with -w.

Related to #20391.

<!--e57a25ab6845829454e8d69fc972939a-->

The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

<!--174a7506f384e20aa4161008e828411d-->

Conflicts

Reviewers, this pull request conflicts with the following ones:

• #20753 (rpc: Allow to ignore specific policy reject reasons by MarcoFalke)
• #20267 (Disable and fix tests for when BDB is not compiled by achow101)
• #19168 (Refactor: Improve setup_clean_chain semantics by fjahr)

If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

Do we need to be aggressive in deprecating this? The estimatesmartfee is still in BTC/kB, so merging this would force all users to do the conversion themselves (or force to pass -deprecatedrpc).

Several reviewers gave feedback that this would be good to fix. If that includes updating estimatesmartfee for a coherent whole, then, like this patch, it's fairly trivial to write and review. If reviewers prefer to hold off, I'll update this patch for 0.22.

Update: currently following the plan outlined in #20484 (comment).

Several reviewers gave feedback that this would be good to fix

Where? I am the first one to comment on this pull.

Regardless, the feature freeze of 0.21 has been a month ago, so I stand by my NACK (at least for 0.21). For 22.0, this could be reconsidered.

Where? I am the first one to comment on this pull.

In #20305.

I agree it makes sense to do this fix as part of the described larger plan, but I hope users won't find it too confusing between now and when the fix arrives in a release.

Removed milestone for now

Update: currently following the plan outlined in #20484 (comment).

This pull proposed to deprecate the feeRate option in fundrawtransaction and walletcreatefundedpsbt to avoid user confusion with fee_rate, as the two params have different units (BTC/kvB and sat/vB) and very similar spellings. However, review has been negative, the plan is currently somewhat stalled, and there has been no interest in resolving this. I think it was necessary to at least propose a solution, can re-open if/when there is demand.