Unify error messages that suggest enabling extensions

The error messages that suggest to enable some extension currently have a lot of slightly different forms: Here are just a few examples (I’ll do a longer search if there is a consensus to move forward with this ticket)

• Did you mean to enable _?
• Did you mean to use _?
• Perhaps you meant to use _?
• Perhaps you intended to use _?

These error messages are parsed by haskell-mode (and maybe other tooling as well) which is quite hard since they have so many different forms.

I propose to change all of those to “Did you mean to enable _?” since that I prefer enable over use here, but I don’t have any strong feelings towards the exact message as long as it’s consistent. So if the majority prefers something else I’m fine with that.