Optimize compressible content selection

[Kaliumhexacyanoferrat]

As a developer of a web application, I would like content that can be compressed well automatically be compressed by the server.

Example

Currently we check for a number of content types. Users should be allowed to extend this logic to their needs, e.g. via

CompressedContent.Default()
                 .Selector((IRequest req, IResponse resp) => true/false);

Could also use the existing logic as a fallback (e.g. via CompressedContent.DefaultSelector()), but this should be documented then. Besides this, the following adjustments to the default logic should be added:

• Remove the .rrd part, this can be custom
• Remove WOFF variants, as they are already compressed
• Add application/xml,
• Move to logic instead of a list for +json and +xml and maybe for all text/ and font/* (except woff)

Acceptance criteria

• The rules have been adjusted as described above
• The feature is documented on the GenHTTP website
• The feature is covered by acceptance tests