Fish and Rarities Cleanup Part 2

[FireML]

I have tested these changes and they seem to be fine. All my fish and rarities load in and I am getting no errors.

• Adds new constructors for Fish and Rarity which take Sections instead of Strings
• Rewrites a lot of Fish methods to use these sections
• Rewrites the loading code to follow these new constructors
• Adds some new methods to Rarity so we don't need to call them in Fish
• Removes some redundant code
• Removes some unused variables
• Deprecates the old Rarity constructor