Implement mirror for yunikorn core APIs in UHS

[sudiptob2]

Currently, the UHS web depends on both the YuniKorn Core and the UHS backend. By implementing a mirror for the following three APIs, we can eliminate the dependency on YuniKorn Core for UHS Web.

This change will streamline the deployment process, as it will no longer require setting environment variables to specify the location of the YuniKorn Core.

APIs to be Mirrored

1. /ws/v1/clusters
2. /ws/v1/scheduler/healthcheck
3. /ws/v1/scheduler/node-utilizations

[sudiptob2]

Implemented in #401