unbound: add test.sh

unbound: add test.sh

unbound-control-setup is a shell script that generates TLS certificates
for unbound-control; it does not print a version string. The generic CI
test framework cannot verify the version via the binary, causing the
"No executables in the package provided version" failure.

Add a package-specific test.sh that:
 - tests unbound-daemon version via 'unbound -V' and config file presence
 - tests libunbound shared library presence
 - tests unbound-anchor/-checkconf/-control/-host binaries run and
   respond to -h without starting the daemon
 - tests unbound-control-setup as an installed, executable shell script
   containing expected keywords (no version check)

Signed-off-by: Alexandru Ardelean <redacted>