9048c58e10 Remove pointer cast in CRPCTable::dumpArgMap (Russell Yanofsky)
14f3d9b908 refactor: Add RPC server ExecuteCommands function (Russell Yanofsky)
6158a6d397 refactor: Replace JSONRPCRequest fHelp field with mode field (Russell Yanofsky)
Pull request description:
This change is needed to fix the `rpc_help.py` test failing in #10102: https://cirrus-ci.com/task/5469433013469184?command=ci#L2275
The [`CRPCTable::dumpArgMap`](16b784d953/src/rpc/server.cpp (L492)) method currently works by casting RPC `unique_id` integer field to a function pointer, and then calling it. The `unique_id` field wasn't supposed to be used this way (it's meant to be used to detect RPC aliases) and as a result, this code segfaults in the `rpc_help.py` test in multiprocess PR #10102 because wallet RPC functions aren't directly accessible from the node process.
Fix this by adding a new `GET_ARGS` RPC request mode to retrieve argument information similar to the way the `GET_HELP` mode retrieves help information.
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This PR is part of the [process separation project](https://github.com/bitcoin/bitcoin/projects/10).
ACKs for top commit:
MarcoFalke:
re-ACK 9048c58e10👑
Tree-SHA512: cd1a01c1daa5bde2c2455b63548371ee4cf39688313969ad2016d9a0fd4344102e3fd43034058f253364518e9632d57cf21abffad0d6a2c0c94b7a6921cbe615