Fix handling of binaryData .url keys

[svolland-csgroup]

This fixes issue #250

[jekkel]

Thanks for your contribution! The fixes look good. Could you please add reproducers for both issues to the test in the github workflow?

[svolland-csgroup]

Tests added, in fact it is only one issue (by fixing only the first point you hit the second point. Both are fixed)

[svolland-csgroup]

You're right it could also mess up with branch builds, I didn't see there already was a local server. Fixed :)

[jekkel]

LGTM

[jekkel]

Run cp test/kubelogo.png test/server/static/
cp: cannot stat 'test/kubelogo.png': No such file or directory
Error: Process completed with exit code 1.

see here

[svolland-csgroup]

Not sure about this fix, i'm completely new to github workflows...