[K8s dashboard improvements] Add dropdown to easy filter page by cloud.provider

[mitodrummer]

To allow a user to easily filter the page by cloud provider, we want to add a dropdown to make this easy.

Requirements:

• For now, we only support AWS and GCP (but lets plan to make it easy to add others, like Azure)
• Choosing an item from the dropdown will cause the whole page to be filtered. There is an open question in the figma about how one goes about clearing this filter. cc @Max-Iskra

Epic: https://github.com/elastic/security-team/issues/4663 Figma: https://www.figma.com/file/BdAcN5SbfW629OMvJrGT2r/%5B8.4%5D-%5BKubernetes%5D-Viz-of-k8s-environment-in-a-topological-view?node-id=3406%3A696744&t=QvdyqaZ7yClJKa5F-0

[Max-Iskra]

When filter is cleared, we are showing stats for both providers if i'm correct. cc @nick-alayil