Dot-notation helper abbreviations

[leodemoura]

During the ICERM after-party hackton, @digama0 suggested we add helper abbreviations such as

abbrev MVarId.getType (mvarId : MVarId) : MetaM Expr 

They are great for discoverability when using dot-notation.

[leodemoura]

@digama0 Any other functions to rename?

[digama0]

I'm going to be making an in depth pass over everything in the coming weeks, so I'll keep an eye out for dot-notation candidates. But I don't have any suggestions at the moment.

[leodemoura]

Closing this issue for now. We can open a new issue for adding new helper abbreviations if someone has suggestions.