Complete removal of Paratext account linking

[Nateowami]

This finishes the work begun in #3938

I have marked it testing not required because I'm not aware of any non-contrived way to reach it, except a system admin joining a project (and therefore not having a Paratext role).

In fact, I think the message could be completely ripped out, but I'm not confident enough to do it just yet.

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This change is 

[codecov]

Codecov Report

❌ Patch coverage is 75.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.95%. Comparing base (aaa62f2) to head (1500af1).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...ipture/ClientApp/src/xforge-common/auth.service.ts	66.66%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3968      +/-   ##
==========================================
+ Coverage   80.92%   80.95%   +0.03%     
==========================================
  Files         637      638       +1     
  Lines       41249    41210      -39     
  Branches     6726     6715      -11     
==========================================
- Hits        33379    33362      -17     
+ Misses       6814     6797      -17     
+ Partials     1056     1051       -5     

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[pmachapman]

I have marked it testing not required because I'm not aware of any non-contrived way to reach it, except a system admin joining a project (and therefore not having a Paratext role).

I agree - I could only get a similar account be logging in with a Google account, then having a system admin manually modify that account to be a project admin.

I think your notice is appropriate for (what I imagine are accidental) cases like this, and perhaps any very old or corrupt user accounts that are not PT accounts but have admin access

@pmachapman reviewed 18 files and all commit messages, and made 1 comment.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on Nateowami).