* Allow for emojis in player name 
- Emojis are typically 3 bytes so player names were failing before bc/
of the size. I increased this to 16 bytes max so characters + emojis can
be a reasonable length.
* Refactor: Add a single instance of the game contract to be used by
multiple functions

(Image shows 24 bytes, but I changed it back to 16 in code)
<img width="402" alt="Screen Shot 2022-11-15 at 5 09 58 PM"
src="https://user-images.githubusercontent.com/2101499/202035698-a21eaef2-ea47-42a2-bf44-fd7dfaff6a87.png">

Lottie animation
-----------------

<img width="1918" alt="Screen Shot 2022-11-15 at 6 14 53 PM"
src="https://user-images.githubusercontent.com/2101499/202044865-f6ddbd1d-15f2-444a-9cd7-43e0eb94dfb5.png">

* Make scoreboard scrollable
* Misc UI changes

Fixes #20 

We can't add an event for scoreboard changes. The contract is not
stateful with regard to the scoreboard and shouldn't be. If this should
be accomplished the Dapp needs to implement it by polling for a specific
game it is watching.

Also changes `(u32, u32)` to a `struct Field { x, y }` everywhere. They
are SCALE compatible so ABIs won't break. Could still break the
frontend. @DoubleOTheven Can you check if your Dapp still works with
this new contract?

This reverts commit b866f255.