feat: add tabs.onRemoved and tabs.onCreated mocks

[RickyMarou]

Hello 👋

I'm a core contributor to Adblock plus and i'm experimenting with using this library to help us write more unit tests. I noticed that it misses a few methods on the tabs API that we would need to make use of, also noticed the issue #107 where somebody else encountered a similar problem.

I took a (very) quick stab at adding those missing methods:

• tabs.onCreated
• tabs.onRemoved

I followed the existing pattern that exists with onUpdated, i.e. I did not implement mock functionalities to make the addListener, removeListener and hasListener work (we could for an example keep track of the functions added as listeners and return correct values in hasListener), but simply mocked them with jest.fn().

Looking forward to feedback to on this 🤞

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 99.51%. Comparing base (c0b1bbf) to head (6d79ad5). Report is 1 commits behind head on main.

:exclamation: Current head 6d79ad5 differs from pull request most recent head c1ce3ba. Consider uploading reports for the commit c1ce3ba to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #180 +/- ## ======================================= Coverage 99.51% 99.51% ======================================= Files 15 15 Lines 207 207 Branches 43 43 ======================================= Hits 206 206 Misses 1 1 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[RickyMarou]

Hey @clarkbw 👋 Anything I can do to get this merged?

I'd actually love to contribute more to this repo, I think it's super useful for extension developers 😊