Add auto ignore phrases and links

[csharpfritz]

As a moderation feature, provide a list of phrases and Urls that should be automatically rejected

Related #307

[JBraunsmaJr]

As a moderator/developer I think it'd be super useful if this supported regular expressions.

Forgive me if it's out of scope or too much. Could be a separate effort/ticket if such a suggestion sparkles with you.

For reference: https://regex101.com/

If I wanted to make sure the regex catches things I'm after, a widget could allow me to create multiple entries. When I write the regex, have it show me what gets caught.

This would help ensure if regex is implemented, we have a way to verify it doesn't horrifically break things.

[csharpfritz]

Sure.. I could see an "advanced mode" where a regex could be provided.

The first glance at this was to create a filter to exclude common swear words, sexual slang, hate speech and links to websites that should be excluded in "safe for work" scenarios.

This work pushes us more towords a message-pipeline architecture where new messages collected from the social media services are sent through a series of filters that act on their content.