Add Opera and Edge support

[basshelal]

Opera uses a similar extensions API to Chrome so it should be pretty straightforward. However Opera does not support chrome.storange.sync according to their website so we'll have to use chrome.storage.local instead.

This is only useful in that we can say we support 3 browsers instead of 2, the number of users that this will add is negligible. Basically it's nice marketing and who knows maybe those 4 guys who use Opera as their daily browser might be grateful.

[basshelal]

We can also probably add Edge support as well since they claim to have an easy transition and use a similar API.

[basshelal]

Wudooh now fully works on Chrome, Edge (Chromium), Opera and Chromium.
Behavior is identical across browsers!
Only sync functionality is slightly different between browsers but the beauty of Chromium means that if there is no chrome.storage.sync then chrome.storage.local is always used instead. This is the case in Opera, basic Chromium and when the user is not signed in to their Google or Microsoft (Edge only) account. In all other cases though, we get the local storage implementation for free.
Nice 😁
I'm still testing this extensively on all 4 Chromium browsers, but unless something drastic comes up I'd say this is done!
Closing!