Pass rpc/misc RPC argument descriptions to RPCHelpMan
Pass rpc/misc RPC argument descriptions to RPCHelpMan

Summary: Partial backport of Core [[https://github.com/bitcoin/bitcoin/pull/14796 | PR14796]]

Test Plan:
  mkdir master
  mkdir patched
On master:
  ninja
  ./bitcoind
  ./bitcoin-cli help > RPCs
  ./getrpchelps.sh RPCs master
On the patched branch:
  ninja
  ./bitcoind
  ./getrpchelps.sh RPCs patched
  ./checkrpc.sh RPCs master patched D5713diff
Verify the changes in `D5713diff`.

Scripts:
{F4246191}
{F4246190}

D5713diff:
{F4249395}

Reviewers: O1 Bitcoin ABC, #bitcoin_abc, jasonbcox

Reviewed By: O1 Bitcoin ABC, #bitcoin_abc, jasonbcox

Differential Revision: https://reviews.bitcoinabc.org/D5713

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