emergency-info-prefs: Robustness tweaks

• Create missing directories when saving keyfile
• If there's no keyfile don't fail silently when adding contacts
• Don't silently ignore contacts without a number
• Update indent
• Avoid some criticals on empty values
• Avoid empty values for multi-value items like "allergies"

/cc @kop3161 @JonathonHall-Purism

Closes: #955 (closed), #960 (closed)

Signed-off-by: Guido Günther agx@sigxcpu.org