[BUG] compute disk create/update split --tags on spaces instead of commas #3998

Describe the bug

compute disk create and compute disk update split --tags on spaces, while the option is documented as "Comma-separated tags in 'key=value' format (e.g., 'env=prod,team=compute')" and compute vm update / compute vmss update split on commas (ComputeService.cs#L1614, #L1715).

Expected behavior

--tags "env=prod,team=compute" sets two tags, env=prod and team=compute.

Actual behavior

It sets one tag, env = prod,team=compute.

Reproduction Steps

The recorded live test DiskCreate_WithLocationAndTags_CreatesWithProperties passes "environment=test,purpose=live-test". In its recording, both the request and the disk returned by Azure have a single tag:

"tags": { "environment": "test,purpose=live-test" }

DiskUpdate_AddTags_UpdatesSuccessfully (environment=test,updated=true) and DiskUpdate_CreateThenUpdateMultipleProperties_FullLifecycle (environment=test,lifecycle=full) recorded the same.

Environment

main at 2d31822.