Check for misspelled atoms

[richcarl]

Atoms in Erlang are sensitive to being misspelled, an the compiler doesn't have a way of checking this. Dialyzer can often detect it, but that has a long turnaround time.

A way to detect this in erlang_ls would be to check atoms in the source file against the levenshtein distance from known atoms in the code and known standard atoms in the system, and warn if the written atom is unknown but very close to some known atom.