[data] optimize Maybe.collect

[matteobilardi]

Problem

The current implementation of Maybe.collect checks if the partial function is defined on the input value before calling it. This can be sub-optimal, as it causes a double evaluation of pattern matchers and guards in the partial function (once on the call to pf.isDefinedAt(value) and once on the application pf(value).

Solution

Using the applyOrElse method allows optimized implementations of PartialFuncion, such as partial function literals (mentioned in https://github.com/scala/scala/blob/780d80c714354871bc5972045926b7ccd042e102/src/library/scala/PartialFunction.scala#L194) to avoid double evaluations of guards.

[fwbrasil]

Welcome, and thanks for the contribution! :)