Add support for unnamed variables

[coehlrich]

Adds support for unnamed variables in:

• Lambda parameters
• Catch statement exceptions (javac doesn't give include an LVT if the catch block is empty)
• Local variable assignments
• For loops
• Pattern variables (pattern matching instanceof with an unnamed variable in an if statement just looks like a regular instanceof. For pattern variables in switches nothing is added to the case statement if the pattern variable is an unnamed variable unless there are multiple for one case)

Still need to do pattern variables in records and fix the guard for multiple pattern variables in one case