Added branch navigation shortcuts

[Cankyre]

Added the navigation keybinds from #251

NOTE: Default keybind to go to start/end (up/down) is remapped to branch start/end and is replaced with shift+up/down

[Cankyre]

Forgot lint fix, sorry for the mess

[franciscoBSalgueiro]

I tried to use "next branch" but it always gives me an error when I use it on the starting position. Maybe adding some tests in store.test.ts would help

TypeError: Cannot read properties of undefined (reading 'fen')
at GameNotation (http://localhost:1420/src/components/boards/GameNotation.tsx:48:21)

[Cankyre]

I fucked the pr, sorry, should be fixed though :/, I'd squash everything if I knew how

[Cankyre]

There, single commit, sorry for the mess again ;>

[franciscoBSalgueiro]

I'm not convinced by the branch shortcuts. It doesn't feel as good as the lichess way of going to the next branch.

For example here:

1. e4 e5 (1... d6 2. d4 (2. d3 )) *

If I go to 1... d6 and then press ctrl-shiftleft it goes forward to 2. d4, which is very unintuitive. Lichess simply goes the next/previous node where there's a branching.

[Cankyre]

Indeed that is strange and not an expected behavior. In this case it should go to 1... e5. That seems to be a bug, I will investigate.

[franciscoBSalgueiro]

1. e4 e5 (1... e6 2. d3) *

It crashes if you go to d3 and press ctrl-right.

Also, why not always go to the next branching point, instead of having a different behavior based on the number branches of the parent?

[Cankyre]

If you always go to the next branching point, there won't be any way to navigate between the variations, making the keyboard navigation incomplete and require the mouse every now and then. A solution can be to have two different shortcuts or a single one that does both actions. I feel like going to the next branching is way less important than switching between branches

[franciscoBSalgueiro]

I agree but having both in the same shortcut is a bit confusing. Maybe having tab for switching between branches when it's in a branching point would be better.

[Cankyre]

I added two shortcuts for the branching point navigation (shift+right/left) and two for switching branch (x/c ; haven't found better)

P.S. I deleted the obsolete tests and have not took the time to make new ones yet, I can do that if necessary.

[franciscoBSalgueiro]

Looks good! thank you