Include backRoute & context in content link on BrowseResourceMetadata

[nucleogenesis]

Summary

Two bugs fixed.

1. When accessing Bookmarked content from Bookmark's page's side panel the route of the content's back arrow would be the Learn Home page.
2. Also if a user would have search context and access the content via the side panel, then they'd have to click the back arrow twice and get sent to Learn Home

This change ensures correct context in both cases.

References

Fixes #8830

Reviewer guidance

First - confirm the two bugs above on release-0.15

This is only when clicking view resource in the side panel when browsing content.

Try it in Bookmarks

Try it in the Library Page - with and without search criteria in place. It should always go back to the state you were in when you left.

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Testing checklist

• Contributor has fully tested the PR manually
• If there are any front-end changes, before/after screenshots are included
• Critical user journeys are covered by Gherkin stories
• Critical and brittle code paths are covered by unit tests

PR process

• PR has the correct target branch and milestone
• PR has 'needs review' or 'work-in-progress' label
• If PR is ready for review, a reviewer has been added. (Don't use 'Assignees')
• If this is an important user-facing change, PR or related issue has a 'changelog' label
• If this includes an internal dependency change, a link to the diff is provided

Reviewer checklist

• Automated test coverage is satisfactory
• PR is fully functional
• PR has been tested for accessibility regressions
• External dependency files were updated if necessary (yarn and pip)
• Documentation is updated
• Contributor is in AUTHORS.md

[rtibbles]

Code makes sense - bookmark backlinks work!