Include information about compliance more often

Also include information about the compliance of a given key even if
not all identities are certified.

Signed-off-by: Justus Winter <justus@gnupg.org>

Refactor compliance code

Refactor the code checking whether a key is compliant into a new
function and export that.

Signed-off-by: Justus Winter <justus@gnupg.org>

Fix selecting the color from a set of filters

Invert the condition. Previously, filters were ignored that presented
a valid color. Now those with a valid color are selected. This was
likely a copy&paste error from 'get_string'.

Signed-off-by: Justus Winter <justus@gnupg.org>

Separate filter code from method to helper function

In the same way that 'bgColor' uses 'get_color'. This makes it
possible to search through two sets of filters.

Signed-off-by: Justus Winter <justus@gnupg.org>

Add and use a second set of key filters

The second set is not part of the model (i.e. it will not be displayed
in Kleopatras drop down list in the default view), and will only be
used for styling keys.

Signed-off-by: Justus Winter <justus@gnupg.org>

Add filters for keys that are (not) VS-compliant

Add a filter that select VS-compliant keys, and two that highlight the
compliance status.

Signed-off-by: Justus Winter <justus@gnupg.org>