Added composer & io to dispatched events, along with on patch fails event

[waleedq]

-Added composer & io to dispatched events to make PatchEvent more standard and to comply with Composer builtin events such as PackageEvent

• Added PATCH_APPLY_ERROR event that will be dispatched when the patch fails to apply

[coveralls]

Coverage decreased (-1.5%) to 36.792% when pulling 26722b9eaa22c5a972758361646d8676d0556462 on waleedq:master into d3b9741e6c40a89114db456cc113304390a52392 on cweagans:master.

[moerazem]

To better understand the purpose of this pull-request, here's a documentation of what we have implemented.

https://docs.varbase.vardot.com/updating-varbase/handling-patches-when-updating

[Natshah]

Thank you very much for cweagans/composer-patches My hope that this pull request got accepted and merged Not sure what is messing to make it pass the automated testing We had been testing this feature in many websites, which eases the work . Add a comment in composer.json to highlight why we're using the vardot/composer-patches repo Vardot/varbase-project#45

Thank you for your time maintaining this very important composer plugin my other hope that if Drupal core start to use it directly in core. or even one more smarter way too