Add full journal filtering support

[dannykopping]

Is your feature request related to a problem? Please describe.
This relates to this discussion in #6656
The sdjournal package does not afford us an easy way to provide AND/OR filtering of journal messages.

cc @carlospeon

Describe the solution you'd like
Implement full journal message filtering to satisfy the Principle of Least Surprise when folks use it, as opposed to the partial support we have now.

Describe alternatives you've considered
N/A

Additional context
Add any other context or screenshots about the feature request here.