[v2] ui: Show key + strings ordering

[MartinFournier]

I cherry-picked @tomitrescak's commit from his PR (#133) so that it would be mergeable, thanks!

Ability to show the key in the UI and sort by the key or translation

Added a few things so that it can be sorted ascending or descending + insensitively.

[gadicc]

Hey, this is really great. Thanks for getting the ball rolling here again and for the extra features. A few things:

1. I'm very against packages uses global template helpers that can leak into the app / other packages. In any case, there's no real need to have a strings() and sortedStrings() method... the original method already had some sort logic, I think all sort logic should simply be integrated into that original function to keep things nice and clean.
2. I'd also suggest a note about clicking on the headings to change sort order, next to the other hints / options.
3. While you're messing around on that line, would be great to add 44f6c92 for v2 :)

Some extras, not required :)

1. Show an up or down arrow next to the appropriate heading for selected sort order. This probably negates the need for (2) above.
2. Option for a 1st level sort order of untrans,fuzzy,trans.

Otherwise yeah I'd say the only real blocker is the global helper and this is some very welcome work!

[MartinFournier]

@gadicc I skipped

Option for a 1st level sort order of untrans,fuzzy,trans.

But otherwise, I think this is complete.

[gadicc]

Legend! Thanks for all the awesome work!