404 errors display [object object] message

[melton-jason]

Describe the bug
When an Http404 error is raised by the backend when saving a resource when webpack is in production mode, the error message is not interpreted/displayed properly by the frontend
Encountered in #5253 (review)

To Reproduce
Steps to reproduce the behavior:

From #5253 (comment):

This other Issue mentioned in #5253 (review) has been fixed as well! Now, a proper 404 error is raised whenever the resource can not be fetched (does not exist/ deleted)

Tested this with treatment event but it does not have the same error message as in the video.

1. Go to Accession
2. Create a Treatment Event
3. Go to that Treatment Event's record
4. Delete the Treatment Event from the db
5. Go back to base record and try to save
6. See that error is different than the comment's error

Report: Specify 7 Crash Report - 2024-11-06T19_18_57.169Z.txt
Link to: https://cuic22024-issue-114-backend.test.specifysystems.org/specify/view/accession/60/

Screen.Recording.2024-11-06.at.1.18.41.PM.mov

From #5253 (review)

When reporting an issue on the production branch or any development version of Specify, please try to recreate the issue on the latest tagged release (v7) and indicate if it does not occur there, indicating a regression.

Expected behavior

Crash Report
Specify 7 Crash Report - 2024-11-06T19_18_57.169Z.txt

If the bug resulted in an error message, please click on "Download Error Message" and attach it here. If there is no error, please follow these instructions to download your System Information.

Please fill out the following information manually:

• OS: Windows 10
• Browser: Chrome
• Specify 7 Version: production (since 144c282)
• Database Name: cuic22024
• Collection name: m
• User Name: spadmin
• URL: https://cuic22024-issue-114-backend.test.specifysystems.org/specify/view/accession/60/

Additional context
This bug only occurs when webpack is in production mode.
In development mode, the proper message is displayed