Remove printers (#2408)

* Remove Brother

- Brother was prone to false positives for everything with a <title> starting with `brother`
- I doubt that the other rule was triggered by anyone.

* Remove Dell, since it had no ways of being detected

* Chai Server is used on other things that HP printers

- Remove the implication on HP for Chai Server
- Remove HP since it can't be detected anymore anyway

* Remove a now unused icon

* Remove a useless file