Add screenshot files cleanup option to Housekeeping

[Antolius]

Add check button for enabling screenshot files cleanup to Housekeeping view. Define a custom icon for screenshot files. Update translation files.

Exposes UI for the Add screenshots to housekeeping #55 task on settings-daemon:

[Antolius]

I removed translation file changes from this PR as well, in line with this comment.

[lenemter]

@danirabbit What do you think of this icon?

[Antolius]

How do we roll this one out to users?

This depends on the new feature added to the settings-daemon. Is there a way to ensure that settings-daemon is upgraded prior to upgrading this settings plugin?

[danirabbit]

Yes we can add a runtime dependency in packaging :)

[Antolius]

Nice work! I’ll update packaging :)

Thank you!