add support for method parameter completions

[gayanper]

This PR adds basic support for completing parameter names with basic parameter suggestion logic.

public class Main {
    public void foo(String ) {}
}

Complete after String

[mickaelistria]

Can you please share an example of code this patch completes better? (to ensure I test the right thing ;)

[gayanper]

@mickaelistria I added the snippet. The current names suggestion are just type name made camel case and combined with the token. No any smart logic is there for better naming

[mickaelistria]

Thanks!