Add intention for replacing explicit function literal parameter with 'it'

Kotlin's function literals have a shortcut for one-argument literals:
the single argument doesn't need to be explicitly named, but can be
referred via the 'it' contextual keyword.

For example, 'array(1, 2, 3).filter { x -> x % 2 == 0 }'
          -> 'array(1, 2, 3).filter { it % 2 == 0 }'

Add an intention action for this transformation.
Add intention for converting an implicit 'it' parameter to an explicitly named parameter

Kotlin's function literals have a shortcut for one-argument literals:
the single argument doesn't need to be explicitly named, but can be
referred via the 'it' contextual keyword. Add an intention action for
converting an implicit 'it' parameter to an explicitly named one.

For example, 'array(1, 2, 3).filter { it % 2 == 0 }'
          -> 'array(1, 2, 3).filter { x -> x % 2 == 0 }'