Make topics a separate query from tags

[ethanstrominger]

As a developer, I would like to be able to select both topics and tags and only find those that match both.

This is a sketch of a UI, but may change during implementation and review.

When you select a topic, it will show the topic as well as the tags associated with the topic and it will be displayed separately from tags. When you select tags, it will show both topics and tags - topics will have the word (topic) in parentheses and when you select that it will populate tags with all tags for that topic.