Merge branch '95-network-error-screen' into 'main'

Add error screen for when device is offline

Closes #95

See merge request !69
1 job for 104-include-supported-api-versions-in-pairing-response in 9 seconds (queued for 8 minutes and 32 seconds)
Name Stage Failure
failed
test Test
Using docker image sha256:c46c61187755b2fc0a535602623032660058bd6d2ab69682c3a8fe0dee0cb73c for briar/ci-image-android:latest with digest briar/ci-image-android@sha256:d06073166283b70fa7c96ce5c94d5adf1ee0f6fac2cad4f51eeb91517a00993c ...
Preparing environment
Running on runner-ypkrwfs-project-202-concurrent-0 via fdroid-gitlab-runner-gcc137...
Getting source from Git repository
Fetching changes with git depth set to 50...
Reinitialized existing Git repository in /builds/briar/briar-mailbox/.git/
fatal: couldn't find remote ref refs/heads/104-include-supported-api-versions-in-pairing-response
Cleaning up project directory and file based variables
ERROR: Job failed: exit code 1