[Feature] Support `type: "hook"` with `mocha/additionalCustomNames`

[TastyPi]

We have a prepareTestContexts function which under the hood calls mocha hooks (before, beforeEach, afterEach, after). I'd like to be able to configure this plugin to treat it the same as mocha's hooks, e.g. complain when not used inside a suite.

Adding hook as a value for mocha/additionalCustomNames seems an obvious way to configure this, if you agree I may take a stab at implementing it over the holidays.

[lo1tuma]

Sounds like a reasonable addition 👍.