more user‐friendly handling of chat commands

1. Come up with a proposal (all-inclusive?) and post it as an Issue (Feature request) on the CHQ repo: https://github.com/Charcoal-SE/SmokeDetector/issues and self-assign it.
   • Problem = users not remembering (or being careful enough with) the strict syntax of some chat commands.
   • Solution = accommodate common user inputs in various chat commands.
   • Alternatives = (a) pick and choose which to implement; (b) leave the chat command parsing as-is.
   • Context = rough search numbers of raw hits and percent-error for the various chat commands.
2. Suggest that the discussion focus on which changes you'd like to see included or excluded.
3. create PR with the consensus and link it to the Issue/FR

Items:

• report: make the whitespace splitting more forgiving (previously https://github.com/Charcoal-SE/SmokeDetector/pull/10755). In situations where multiple spaces exist after the URL(s) and before the custom reason, users receive the message "That does not look like a valid post URL". The code change would be to use string.split()'s behavior with sep=None to regard runs of consecutive whitespace as a single separator (https://docs.python.org/3.3/library/stdtypes.html#str.split). This change would also allow for multiple spaces between URLs.

• reject: allow for optional double-quotes around the reason; it would accept commands like: !!/reject 12345 5 false positives, no known hits.; the code change would look for: "\d+" then 19+ characters, regardless of double-quotes

• reject: allow for commonly-used reasons that are too short. Blacklisters often close a PR with short reasons, such as "superseded by 12345" or "at author's request", or "requested by author" (both 19 characters!). This change would allow a short reason (less than 20 characters) if: matched by: 'superseded by \d+' or (match('author') && match('request')).

• addblu / rmwlu / iswlu: allow a trailing comment (and just throw away the comment); might be better placed in get_user_from_list_command, which would modify multiple commands' behavior

• skip this; code was added specifically to catch it:

  • watch: allow (and strip) leading whitespace in the pattern; there's specific code to watch for this: if regex.search(r"^\s+", pattern): other_issues.append("The pattern starts with whitespace.") Spevacus committed on May 12, 2021 added that code.
  • consider a separate PR that would (silently) strip leading and/or trailing whitespace from the pattern

Context:

command	error response	count error	total command (total search hits)	error %
report	That does not look like a valid post URL	276	32085	0.86%
reject	Please provide an adequate reason for rejection (at least 20 characters long) so the user	78	1286	6.06%
blacklist-keyword	"The pattern starts with whitespace."	68	30926	0.22%
addblu	"Invalid format. Valid format: !!/addblu profileurl or !!/addblu userid sitename."	40	1677	2.38%
isblu	"Invalid format. Valid format: !!/isblu profileurl or !!/isblu userid sitename."	33	629	5.24%
rmwlu	"Invalid format. Valid format: !!/rmwlu profileurl or !!/rmwlu userid sitename."	5	64	7.81%