PB-1954: implement otel instrumentation

Currently, the regex for preventing qrcoding URLs other than map.geo.admin
can be bypassed, e.g. by map.geo.admin.ch.attacker.com, since the regex is too weak.
Hence the regex was anchored to make sure, that the URL to be qrcoded is exactly
map.geo.admin.ch, rather than checking, that the string is somewhere in the URL.

PB-2205: regex too weak

Using fullmatch() instead of match() only makes the service safer.
This way, even if the regex is not anchored, map.geo.admin.ch.evil.com
bypass trick will still be detected by the fullmatch and blocked.
Otherwise the regex needs to be anchored.

…allback

PB-2205: using re.fullmatch() instead if re.match()