Adds the TypeHintTappableCallRector

[peterfox]

Changes

• Adds the new TypeHintTappableCallRector rule
• Adds tests for the rules
• Adds a stub for the Tappable trait

Why

Should be a neat rule to help people automatically type hint the tap method.

-tap($collection, function ($collection) {}
+tap($collection, function (Collection $collection) {}

-(new Collection)->tap(function ($collection) {}
+(new Collection)->tap(function (Collection $collection) {}

[peterfox]

Thank you for catching those @GeniJaho 😄