Merge #10753: test: Check RPC argument mapping

Merge #10753: test: Check RPC argument mapping

77aa9e59e test: Check RPC argument mapping (Wladimir J. van der Laan)

Pull request description:

  Parse the dispatch tables from the server implementation files, and the conversion table from the client (see #10751).

  Perform the following consistency checks:

  - Arguments defined in conversion table, must be present in dispatch table. If not, it was probably forgotten to add them to the dispatch table, and they will not work.

  - Arguments defined in conversion table must have the same names as in the dispatch table. If not, they will not work.

  - All aliases for an argument must either be present in the conversion table, or not. Anything in between means an oversight and some aliases won't work.

  Any of these results in an error.

  It also performs a consistency check to see if the same named argument is sometimes converted, and sometimes not. E.g. one RPC call might have a 'verbose' argument that is converted,
  another RPC call might have one that is not converted. This is not necessarily wrong, but points at a possible error (as well as makes the API harder to memorize) - so it is emitted as a warning (could upgrade this to error).

  This test is added to travis and run when `CHECK_DOC`. Currently fails with the following output:
  ```
  * Checking consistency between dispatch tables and vRPCConvertParams
  ERROR: createrawtransaction argument 3 (named optintorbf in vRPCConvertParams) is not defined in dispatch table
  ERROR: getblock argument ['verbosity', 'verbose'] has conflicts in vRPCConvertParams conversion specifier [True, False]
  WARNING: conversion mismatch for argument named verbose ([('getblock', False), ('getblockheader', True), ('getmempoolancestors', True), ('getmempooldescendants', True), ('getrawmempool', True), ('getrawtransaction', True)])
  ```
  - ~#10698 fixes the first ERROR~
  - #10747 fixes the second ERROR, as well as the WARNING

  Update: #10698 was merged, leaving:
  ```
  * Checking consistency between dispatch tables and vRPCConvertParams
  ERROR: getblock argument ['verbosity', 'verbose'] has conflicts in vRPCConvertParams conversion specifier [True, False]
  WARNING: conversion mismatch for argument named verbose ([('getblock', False), ('getblockheader', True), ('getmempoolancestors', True), ('getmempooldescendants', True), ('getrawmempool', True), ('getrawtransaction', True)])
  ```

Tree-SHA512: feabebfbeda5d4613b2b9d5265aa6bde4e1a0235297ffd48fa415ad7edc531d9ed7913fe76d191ac60d481a915a326f216bc93de3c671e45e1d14e97d07dea7a