capa Explorer Web: improve url navigation

[s-ff]

closes #2419

This PR enhances the navigation in capa Explorer Web by making sure the links generated are shareable. Preview.

Previously: users browsing to /analysis were always redirected to the homepage /.

With this PR:

• If a user accesses /analysis without an rdoc query parameter set in the URL, they are still redirected to the homepage.
• If a user accesses /analysis with the rdoc query parameter set, capa Explorer Web loads from that URL instead of redirecting to homepage.

Checklist

• [ ] No CHANGELOG update needed
• [ ] No new tests needed
• [x] No documentation update needed

[mr-tz]

TODO @s-ff: VirusTotal links have a short lifespan before expiration, add a toast message mentioning this instead of just "HTTP error 400"

will you create a separate PR for this?

[s-ff]

TODO @s-ff: VirusTotal links have a short lifespan before expiration, add a toast message mentioning this instead of just "HTTP error 400"

will you create a separate PR for this?

Yeah, I just created #2427 for tracking

[mr-tz]

Thanks @s-ff!