[BB-3171] Prevent race condition that can delete user input

[viadanna]

This PR changes how Account fields are updated in the UI so that updating the fields in quick succession does not cause previous XHR requests to remove information.

JIRA tickets: BB-3171

Merge deadline: "None"

Testing instructions:

1. Check out this branch in your master devstack.
2. Log in to the LMS and go to your Account Settings.
3. Open the DevTools and Enable slow 3G throttling.
4. Update the Account information in quick succession, keeping an eye on the DevTools Network tab.
5. Make sure no previously entered information is lost.

[openedx-webhooks]

Thanks for the pull request, @viadanna! I've created OSPR-5633 to keep track of it in JIRA, where we prioritize reviews. Please note that it may take us up to several weeks or months to complete a review and merge your PR.

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[edx-status-bot]

Your PR has finished running tests. The following contexts failed:

• jenkins/quality

[natabene]

@viadanna Thank you for your contribution. Please let me know once it is ready for our review.

[viadanna]

This ended up being a duplicate of https://github.com/edx/edx-platform/pull/25950

[openedx-webhooks]

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