Compact block cache pt2

[idky137]

This is the second PR adding the internal compact block cache to the FetchService in zaino-state.

• Updates Zaino's config files and example config (zindexer.toml) by adding the new options required for integrating the BlockCache into the FetchService.
• Removes old (unused) config options.
• Updates Zaino-Testutils TestManager to handle new config options.
• Adds several review changes to the BlockCache.

The actual BlockCache integration will be done in the following PR.

[AloeareV]

I'm noticing a lot of boilerplate in the tests, I think that is where I will focus next!