Allow showing more content in sources

[adamrdrew]

The preview content in message sources is too short to be useful. It would be better if it showed more, and better still if I could control how much it shows. Adding a modal to view the entire source might be nice.

[rebeccaalpert]

I can bring this up for discussion with the team at our weekly call.

[rebeccaalpert]

Kayla's going to look into adding native support for this use case with more information presented - will update this as this progresses.

[rebeccaalpert]

See related design issue: patternfly/patternfly-design-kit#785

[rebeccaalpert]

Design is complete: patternfly/patternfly-design-kit#785