Add ability for admins to force break a queue and set the mmr multiplier

[mattwells19]

Description

Add admin slash commands with the following abilities:

• forcebreakq: Removes an active match. Requires a player in a match to be provided to know which match to remove.
• mmrmult: Updates the MMR multiplier for the current Event.

Acceptance Criteria

• Only members with the Bot Admin role can successfully execute these commands.
• All responses are "ephemeral."
• Issuing the force broken queue command removes the active match that contains the specified player.
  • Reference the kick command on how to require a player to be specified.
• Issuing the MMR multiplier should accept a parameter for the new multiplier
  • Can be a decimal or whole number
  • Cannot be less than 0 (but can be 0)
• Entering an invalid MMR multiplier should respond with an appropriate message and not change the MMR multiplier.

Technical Details

The check for the Bot Admin role is already implemented in AdminController so that shouldn't need to change.
Be sure to reference the existing kick and clear admin commands for registering and handling slash commands.
This does not include actually using the MMR multiplier when reporting matches. That will be done as part of a separate issue.