Extend Test Reporter to be better extendible beside others

[bambamboole]

Hey, thanks for merging the other PRs. We are now able to use the qase reporter in our project.
While setitng it up, I came across a few things we would like to configure.
I made here a POC on what we are doing. Would be cool to get your opinion on this.

• Make QaseReporter private methods protected. It is way easier to extend and change behaviour by being able to call existing methods.
• Reset $this->currentKey after test was completed. This supports other methods checking of currentKey is actually set.
• Add new PhpUnitConfig class with factory to create from phpunit.xml parameters.
• config value which enables to only report tests which actually have a test suite. For us its important to not get these arbitary test suite names in qase.io we only want to sync the one which are also marked in phpunit.
• Add config value to change how a missing test case title is made.

[bambamboole]

Converted it to draft. so that we can first get the config injected in the php-commons package. then we can leverage this here

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.