SUBMARINE-1296. Add create user function when register a new user.

[hhcs9527]

What is this PR for?

Originally we were unable to create a user correctly; We add create user function when registering a new user in this PR.

What type of PR is it?

[Bug Fix | Improvement | Feature | Documentation | Hot Fix | Refactoring]
Bug Fix

Future work

• When we log in to the account, it always shows adim in the userInfo
• Remove the mock data in here

What is the Jira issue?

SUBMARINE-1293

How should this be tested?

Screenshots (if appropriate)

• When you haven't created such a user

• When you save duplicated username

• Done creation and log in again

Questions:

• Do the license files need updating? No
• Are there breaking changes for older versions? No
• Does this need new documentation? No

[codecov]

Codecov Report

Merging #1012 (e118d81) into master (bc4bf08) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master    #1012   +/-   ##
=========================================
  Coverage     25.47%   25.47%           
  Complexity     1079     1079           
=========================================
  Files           358      358           
  Lines         29088    29088           
  Branches       3479     3479           
=========================================
  Hits           7411     7411           
  Misses        21463    21463           
  Partials        214      214           

Flag	Coverage Δ
python-integration	59.58% <ø> (ø)
python-unit	52.18% <ø> (ø)

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[hhcs9527]

@cdmikechen please take a look at the pr, thanks
I can't add reviewer due to permission issue.

[cdmikechen]

I suggest that we can show the changed result under the screenshot.
Others LGTM