* Infer from arrows from usage.
Previously only function expressions were, and only those with an easily
accessible name. Now any arrow function or function expression will
infer from usage.
* remove isApplicableFunctionForInference
*all* functions are applicable for inference now.
* add fixAwaitInSyncFunction code fix
* Just insert the keyword
* only one codefix
* remove comment
* Change explicit return type T to Promise<T>
* Review changes
* Change codefix message