Lint `'static` lifetimes in the type of statics/consts

[oli-obk]

see rust-lang/rust#41957 (comment) for an example

RFC 1623 allows writing const FOO: &str = "bar" instead of const FOO: &'static str = "bar"

[gbip]

I might want to implement this lint as a first contribution, but first I have to make sure I have the time to do so.
I will keep you updated !

[mcarton]

@gbip Great! Don't hesitate to ask if you have any question.

[oli-obk]

This has been implemented in #2151