Updated to fix issues-4170

[mohankumarelec]

Description

Closes: #4170
This PR fixes the issue and adds feature of linkProviderUserInfo in auth emulator.

Scenarios Tested

• should error if linkProviderUserInfo is missing required fields
• should error if user is disabled when linking a provider

[joehan]

Note: Needs a CHANGELOG entry before merge.

[yuchenshi]

PTAL at the unit test failures and I can do another round of review after

[yuchenshi]

I think we're just missing one entry to CHANGELOG.md as Joe said, and then we're ready to merge as soon as the CI completes.

[yuchenshi]

The assertion conditions seems flipped, which breaks unit tests. Please see suggested fixes. Please also add a CHANGELOG entry.

CI failure: https://github.com/firebase/firebase-tools/actions/runs/12128407551/job/33814720138?pr=7980#step:6:4129

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 51.14%. Comparing base (e895fd2) to head (13549f5).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #7980   +/-   ##
=======================================
  Coverage   51.14%   51.14%           
=======================================
  Files         423      423           
  Lines       29581    29585    +4     
  Branches     6043     6045    +2     
=======================================
+ Hits        15128    15132    +4     
  Misses      13094    13094           
  Partials     1359     1359           

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[yuchenshi]

This has been released in Firebase CLI v13.28.0. @mohankumarelec Thanks for the contribution!