Integration of the APM RUM instrumentation on New Platform.

[vigneshshanmugam]

Integration of the APM RUM instrumentation on Kibana new Platform.

• We already have a working instrumentation on the old platform through the injected metadata service.
• With the instrumentation, we should be able to hook in to the page-load and route-change events and capture those changes via the RUM agent.

More details on how its done for the old platform - #44281

[pgayvallet]

Ping @elastic/kibana-platform for the legacy platform, APM is hooked into the angular router event (see #44281)

Not sure how we want to address this in NP: is ApplicationService.currentAppId$ enough for this, or should we implements a way to 'hook' into ApplicationService.navigateToApp?