Create failure kinds

The fixed error_kind words a failed sandbox or Space create sends, and what each means.

When a create fails, cua_space_create, cua_sandbox_created and cua_host_space_provided set error_kind to a fixed word for the cause. The program reads the error on your machine and sends only the word, never the error text.

`error_kind`	Cause
`image_pull_not_found`	The image is not in the registry.
`image_pull_auth`	The registry refused the download.
`image_pull_network`	The network failed or timed out during the download.
`image_pull_rate_limited`	The registry rate-limited the download.
`image_pull`	The download failed for another reason, or stopped partway.
`insufficient_disk`	Not enough disk space.
`runtime_missing`, `runtime_not_running`, `runtime_permission`	The local runtime (Docker, Lume, QEMU) is not installed, not running, or not allowed.
`virtualization_unavailable`	The machine cannot run VMs (no Virtualization.framework, KVM or hardware virtualization).
`vm_limit`	The Mac already runs the two macOS VMs Apple allows.
`vm_boot_timeout`	The VM did not finish booting in time.
`services_unreachable`	The Space booted but its services never answered.
`local_network`	macOS Local Network privacy blocked the connection to the new VM.
`quota_exceeded`	The account's quota, plan limit or credits ran out.
`cancelled`	You cancelled the create.

Otherwise it is the error's type (for example unauthenticated, timeout, runtime), and other only when nothing names the cause. A failed create never reports none.