PathPrefix for karmada dashboard

[warjiang]

What would you like to be added:
Add PathPrefix feature for karmada dashboard

Why is this needed:
Typically, enterprises differentiate various functional systems or business lines through multiple paths under a single domain name.

The Karmada dashboard was initially designed with the expectation that users would expose dashboard-related services via nodePort or a dedicated ingress domain. However, this design does not adequately address the needs of enterprise privatized deployments.

Each enterprise's on-premises deployment configuration has a unique path prefix. While generating frontend assets with different path prefixes can support on-premises deployments, this method is costly (requiring builds for each enterprise's pathPrefix) and inefficient (requiring repetitive builds for each upgrade).

Therefore, we hope that the Karmada dashboard can implement pathPrefix capabilities through configuration, supporting the needs of enterprise’s on-premises deployments.

The overall workflow is illustrated in the following diagram:

[warjiang]

/assign