add no-CTCP user mode

[slingamn]

We added +C as a channel mode for channels (copying unreal).

We should add a corresponding mode for users. Unreal uses +T (presumably because +C was conflicted with their "co-admin" mode?). We should probably just copy this rather than using +C for the user mode as well.

[slingamn]

This should be fairly simple once the decision about which mode to use has been made. Any time we check IsRestrictedCTCPMessage against whether the user is coming from Tor, also add a mode check.

[DanielOaks]

Yeah Insp uses +T as well so we can assume that's fairly universal, cool: https://github.com/inspircd/inspircd/blob/90e64cbacefbc74a832b9389cf9b229fb9bfb4ee/docs/conf/modules.conf.example#L1473

[slingamn]

@clukawski is looking at this.

[clukawski]

ok figured out what was wrong here i'll wrap this up tomorrow 👍