Support CCS in Universal Profiling

[stuartMoorhouse]

Univeral Profiling to support seeing profiling data from multiple clusters, connected via cross-cluster search

The use case is have a multi-cluster topology, with observability data from different lines of business going into different clusters and being able to see Profiling for all of them without having to copy all the data into one central cluster to do this.

For some users copying all the data could be cost-prohibitive. Also, other parts of the Observability application, like APM, support CCS so it would be consistent if Profiling does as well.

[elasticmachine]

Pinging @elastic/obs-ux-infra_services-team (Team:obs-ux-infra_services)