WIP: Plasma mobile telephony in user interface

Opening this as a MR to keep state of the branch known, and to keep each change documented, likely each patch will be merged as a separate granular MR, so feel free to ignore this MR.

Status of the commits,

• kde/plasma-{nano,phone-components,settings} (!652 (closed))
• telepathy-ofono: ask upstream to merge the patch
• kde-plasma-phone-components/blurb.patch: try to push nicer version upstream
• dontbeevil/librem5dev/pinephone: open a separate MR for adding ofono to startup (!678 (closed), !679 (closed))
• package and enable urfkill (!638 (closed))
• update plasma-phone-components so that nicer version of blurb.patch is built (!680 (closed))
• allow wheel group to access ofono dbus so Plasma/Telepathy can actually talk with ofono (!749 (merged))