Add Option to Choose Piece Color

[aashutoshrathi]

Description

As of now, the UI is hardcoded to give white pieces to whoever starts the game. The Micro-rollup on the other hand takes the color input in the JoinGame payload.

Extend the UI so the player can choose the color of the pieces.
The ideal implementation would be a modal that pops up when you click on "Create Game". This modal can later have more fields too.