Small cleanup and support for color=always in pw-dump

First commit is just removal of two fields that are only initialized, but never really used in code.

2nd commit adds ability for a user to pipe pw-dump output to less utility without losing all the fine colors. It's very useful for this utility, given it usually gives so much output, it's ever larger than default Konsole scrollback.

Note: I didn't remove the older option -no-colors for backward compatibility, but if maintainers wish, I can delete it as well.