ui: prevent /_status/nodes calls for secondary tenants

[kyle-a-wong]

/_status/nodes is not implemented for secondary tenants, resulting in 501 responses in cloud for serverless tenants. To fix, this api is now gated by a tenant check and will no longer be called by serverless / secondary tenants.

Fixes: CC-26900 Epic: None Release note: None

[cockroach-teamcity]

This change is 

[kyle-a-wong]

bors r+

[craig[bot]]

Build failed:

• unit_tests

[kyle-a-wong]

bors retry

[craig[bot]]

Build succeeded:

• windows_build
• examples_orms
• check_generated_code
• macos_arm64_build
• docker_image_amd64
• unit_tests
• linux_arm64_build
• acceptance
• macos_amd64_build
• lint
• local_roachtest
• linux_amd64_build
• linux_amd64_fips_build
• local_roachtest_fips