Rule simplify_code_using_streams should check for variables that are not effectively final

[lyxell]

Since simplify_code_using_streams creates a lambda expression we need to check that the variables referenced in the lambda expression are effectively final.

[lyxell]

This applies to simplify_code_using_map_computeifabsent as well

[lyxell]

When fixed these rules should be enabled in the compile-maven build step