Extract overall stats table

[darkspirit510]

Currently, the BenchmarkScore class is a mix of Maven stuff, delegations, calculations and HTML. Moreover, HTML code exists in some other classes. I'd like to extract all the HTML stuff to its own sub package and just call it, so it's clear what code belongs to the final report.

This is the first PR that picks one table - in that case the overall stats table - and extract it to its own class without access to any static/global variable.

[darkspirit510]

Just converted this to draft - want to add some Tests first 🙈

[davewichers]

OK, I didn't look at this too deeply but all the test cases and most of the changes are creating new classes, so I merged this. This seems like a good step forward to organize all this stuff better. Thx