Cloudwatch: Add monitoring badge for metric insights

[idastambuk]

What is this feature?

Adds a monitoring badge as part of https://github.com/grafana/oss-plugin-partnerships/issues/886, under metricInsightsCrossAccountEnabled feature toggle.

Why do we need this feature?

part of https://github.com/grafana/oss-plugin-partnerships/issues/886

Which issue(s) does this PR fix?:

Fixes https://github.com/grafana/oss-plugin-partnerships/issues/971

Special notes for your reviewer:

Please check that:

• It works as expected from a user's perspective.
• If this is a pre-GA feature, it is behind a feature toggle.
• The docs are updated, and if this is a notable improvement, it's added to our What's New doc.

[sarahzinger]

I think we don't need to add this to changelog tho, maybe we can do that when its ready for testing