Improve item get messages

[Chris-Is-Awesome]

• Use item type/flags to change text colors based on them
• Cache icon textures
• Reduce time for messages if 10+ in queue
• Think of way to better handle adding messages in quick succession (like with 3x card rooms)

[GameWyrm]

Caching textures should be part of ModCore as a feature of the GetTextureFromFile method.