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

Description

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.

Won't Do

Assignee

Unassigned

Reporter

Open Source Pull Request Bot

Labels

Contributor Name

Paulo Viadanna

Repo

edx/edx-platform

Customer

Epic Link

None

OSCM Assignee

None

Platform Map Area (Levels 1 & 2)

None

Platform Map Area (Levels 3 & 4)

None

Blended Hour Utilization Percentage

None

edX Theme

None

edX Squad

None

Github Lines Added

20

Github Lines Deleted

2

Priority

Unset