Allow hiding badge counter

[max-baz]

Note this implementation doesn't just prevent entering updateMatchingPasswordsCount() function (as I personally initially expected), but only prevents doing what is hopefully the most expensive computation: getting a huge array of files and processing them.

This way, when a user toggles badge option we would refresh the badge instantly, and also if a user puts hideBadge in their .browserpass.json we would detect it within a minute. This also means that tab update handler still executes and it still refreshes settings every minute.

I would be really interested to know if this solves #224, @elprans if you could try this PR it would be much appreciated.

@erayd what do you think in general?

Fixes #224 Fixes #103 Fixes #342 Fixes #348

[erayd]

@maximbaz Do you need me to do performance testing on this, or have you verified that bit already and just need code review?

[max-baz]

Performance test would be appreciated, no I don't know for sure that it solves #224

[erayd]

Sweet, I'll test that aspect first then.

[max-baz]

This is very requested feature recently, and multiple people have tested this PR. I've just rebased it on latest master. I think it makes sense to merge it, @erayd would you like to review this before then?