qapi: Move @String out of common.json to discourage reuse

Use of String is problematic, because it results in awkward interface
documentation.  The previous commit cleaned up one instance.

Move String out of common.json next to its remaining users in net.json
to discourage reuse elsewhere.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240205074709.3613229-15-armbru@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
3 files changed