Redesign user settings UI

[jschwartzentruber]

Merge MozillaSecurity#15

Demo video: https://www.loom.com/share/5f0f300cad1b4924bb824fc762460bb0

[pyoor]

Closes #1005.

[codecov]

Codecov Report

Attention: Patch coverage is 98.14815% with 1 line in your changes missing coverage. Please review.

Project coverage is 63.38%. Comparing base (981eed7) to head (092be62).
Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
...erver/frontend/src/components/UserSettingsForm.vue	97.72%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1042      +/-   ##
==========================================
+ Coverage   63.26%   63.38%   +0.11%     
==========================================
  Files         158      159       +1     
  Lines       11065    11112      +47     
  Branches      648      420     -228     
==========================================
+ Hits         7000     7043      +43     
- Misses       4037     4041       +4     
  Partials       28       28              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.