Bug#969769: ability to filter on severity when listing all tags

[Felix Lechner <felix.lechner@lease-up.com>]

Hi Jelmer,

> At the moment, classification tags are excluded manually

I'll think of a good way to address your issue, but wanted to cue you
in that classification tags are on the way out.

Lintian is being split into two parts (internally). One provides
scanning (similar to lab results in medicine) and the other provides
the evaluation (like a doctor's diagnosis). Classification tags are
scanning results and have nothing to do with the diagnosis.

Direct access to Lintian's scanning results, which will be provided in
ever greater numbers, should be very useful to many automated tools in
the Debian ecosystem, such as Lucas's Trends, and perhaps even to the
Janitor. An example for this new direction is the tag trimmed-field.

Kind regards
Felix Lechner