Add the reason to xline removal notices. (#1545)•••Show the reason in manual xline removal SNOTICEs, just like
expiry SNOTICEs do.
This modifies XLineManager::DelLine() to require another string
reference passed to it.
Requested by @Robby-.
Improve X-line text consistency.•••- Change any "-Line", ":Line", or "*line" to "-line" throughout
the X-line code, comments, and documentation.
- Add periods to the end of some notices.
- Correct a typo in the Q-line code comments.
- Update the filter module documentation (shun addition).
Co-authored-by: Robby <robby@chatbelgie.be>