mgr/dashboard: introduce grafana frontend e2e testing

mgr/dashboard: introduce grafana frontend e2e testing

Used the https://www.npmjs.com/package/@grafana/e2e npm packages and
followed
https://github.com/grafana/grafana/blob/main/contribute/style-guides/e2e.md
to understand the style of the grafana e2e testing.

In this PR I introduces the tests for the Hosts Overall
Performance and also RGW per Daemon and Overall Performance

Fixes: https://tracker.ceph.com/issues/54356
Signed-off-by: Nizamudeen A <nia@redhat.com>