WIP: Add functionality to look-up and display chart on embeddable Insights page

What does this MR do?

This MR adds logic to add the chart queried through the params to the page.

This MR is not done but shows the general approach. Still missing is:

• Add tests
• Verify different edge-cases, e.g. wrong queries, corrupt chart data, failure to fetch data
• Ensure that copy is good and verified

Screenshots

Embedded into a page	The embeddable page itself

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

You can test this out by applying this patch and navigating to http://127.0.0.1:3000/Commit451/lab-coat/insights: test_embeddable_chart.patch

This has minimal risk as this is presented behind a feature flag: embed_analytics_report.

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Related to #224192 (closed)

Dependent on !36334 (closed)