Update to 1.9.10, add GIM chat support, multiple refactors

[Ririshi]

This PR is an update and small overhaul of the plugin.

The following changes have been made:

• Update the plugin to be compatible with RL 1.9.10
• Added support for GIM chat, based on the in-game GIM chat colors
• Precompute colors based on RL and in-game settings, only updating colors if the settings change
• Save the open chat panel instead of the chat channel for better channel detection
• Tracking whether player is in a friends chat to accurately predict the channel that a message will go to
• Refactored enums into their own class file
• Reformatted code to max width of 80 characters