This is a followup to #9656 and implements the following step mentioned in that PR:
* When possible, extract all the help and completion tips from COMMAND DOCS (Redis 7.0 and up)
* If COMMAND DOCS fails, use the static help.h compiled into redis-cli.
* Supplement additional command names from COMMAND (pre-Redis 7.0)
The last step is needed to add module command and other non-standard commands.
This PR does not change the interactive hinting mechanism, which still uses only the param
strings to provide somewhat unreliable and inconsistent command hints (see #8084).
That task is left for a future PR.
Co-authored-by: Oran Agra <oran@redislabs.com>
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