striker-collect-debug compress speed vs size optimization

we recently noticed that debug collection time in CI is extremely high. initially we thought that it was due to collecting screenshots (see #620 ) but in reality that´s not the case.

anvil.logs are in the order of GBs after only one hour run. This takes forever time to compress with bzip2 in default config.

A decent compromise for CI would be to add a new option for striker-collect-debug 'fast-compresss' that will set bzip2 -1 for the final tarball creation.

For a couple of simple benchmarks, this reduced the compress time by half, at the cost of doubling the final tarball size. Customers can than chose what they prefer based on their storage/network settings.

I have a patch ready in case we agree to go down this route.