BUG: properly handle out-of-context no-payload commands

bug description

• SYMPTOM: when subscriber sends a hotline message that says "Hello i want to report an incident" they get a response that says "Sorry, that command was not recognized. Did you mean to use HELLO"?
• CAUSE: parse.validateNoPayload returns a parse error for all no-payload commands that are followed by a payload, meaning that what should be interpreted as a hotline message is handled as a commandResult with status ERROR once it hits dispatcher.messenger.parseMessageType (see: https://0xacab.org/team-friendo/signalboost/-/blob/main/app/dispatcher/messenger.js#L67-70), where to be interpreted as a hotline message it would have to have command type NONE and status SUCCESS (but it has command type JOIN and status ERROR
• FIX: TBD! probably add some logic to the command.execute layer that coerces the type of any such message to NONE and its status to SUCCESS (likely as an early-returning returnIfHotline that is called just above the switch statement in execute#execute, which checks to see if the sender is a subscriber and hotline messages are enabled and returns early with a coorced type/status if so. maybe group this with the other special casing parse error-handling logic we currently have above the switch statement)

desired behavior

GIVEN hotline messages enabled

• WHEN a subscriber sends Hello everyone or Accept the consequences (or any other no-payload command, see below)
• THEN the message should be treated like a hotline message and forwarded to admins

GIVEN hotline messages disabled

• WHEN a subscriber sens Hello everyone (or any sentence starting with a 1-word command)
• THEN the message should trigger an error message:
  • IF command is issuable by subscriber/rando (see below)
    • THEN respond with current error message. ("did you mean to X?")
  • IF the command is not issuable by a subscriber
    • THEN respond with a generic "i don't understand, i didn't send that, use HELP" message
    • TK-TODO: what is this "generic" error message?

GIVEN hotline messages in any state

• WHEN an admin or rando sends Hello everyone it triggers the "no payload" error message above (potentially we should add "were you trying to send a broadcast message?" to error for admins?)

definitions

the set of "no payload commands" is:

subscriber:

• ACCEPT
• DECLINE
• HELP
• INFO
• JOIN
• LEAVE
• SET_LANGUAGE

admin-only:

• DESTROY
• DESTROY_CONFIRM
• HOTLINE_ON
• HOTLINE_OFF
• VOUCHING_ON
• VOUCHING_OFF
• VOUCHING_ADMIN