Multi selection of authors should be OR not AND

[adamjonas]

When filtering by author any check box indicates an OR operand not the current status of AND

[aassoiants]

^ should then also be the same for the Source

"As a user i want to know if [string] is found in [source a] OR [source b]"

Down the road we might explore advanced search, but that's farrrrrrrrrrrr backlog

[kouloumos]

@Emmanuel-Develops I think that we should prioritize this. This is useful functionality for both Authors and Domains. We will needs this for Bitcoin Transcripts as well.

Filtering "by Topic" is a functionality that we will need as we start to add topic tags to more resources (already a thing for Bitcoin Transcripts resources), and that needs OR instead of AND as well.