Resolve issues with editing and browsing newly added topics

[bjester]

Summary

Description of the change(s) you made

• @ozer550 and cohacked on this
• Prevents making HEAD requests to the backend if the requested resource may not have been created on the backend yet, preventing 'Page not found' when opening newly created folders
• Fixes issue opening non-existent tabs in the edit modal, causing a blank screen when editing details

Manual verification steps performed

For #3699

1. Stop celery
2. Open a channel for editing
3. Create a new folder
4. Open the folder
5. Verify you don't see 'Page not found'

For #3681

1. Click to edit the channel's details
2. Click the Sharing tab
3. Close the modal
4. Click on the kebab menu for a folder
5. Click to create a new folder
6. Verify the edit modal details fields aren't missing

References

Fixes #3699
Fixes #3681

Comments

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Contributor's Checklist

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[rtibbles]

When testing the fix for #3699 I can confirm that I no longer see 'page not found', but instead I get a 400 on the request to get child nodes, and it stays in a permanent loading state:

I think maybe just catching the 400 here might be needed?

Fix for #3681 confirmed.

[bjester]

@rtibbles Ah we had commented out the fetchCollection in the where method during our testing, but restored it during commit. That's where the 400 is coming from, so a further change there is needed. Working on it

[rtibbles]

Code changes make sense, manual testing checks out!

[pcenov]

Excellent, both issues are fixed now!