Function Compiler

Adds commands:

• execute rotated as
• execute rotated
• execute positioned as

Fixes bugs:

• team selector overwrites previous team selectors
• team selector fails to compare team names properly
• Positions fail to parse with a ~ without a number after it
• Using objectives which don't exist causes an exception when running the command
• Using a command that accepts a scoreholder can break at compile time (affects execute if score only)
• Comparing two scores together reverses the operator (a <= b became b <= a in compiled code)
• 1.20.1 code fails to call external functions due to missing access widener entry
• Some selectors fail to parse properly with whitespace