Migrated /enterprise/auth_sso tests to TypeScript

[Tert0]

Summary

Converted following file to TypeScript:

• authentication_spec.js
• mfa_authentication_spec.js

Ticket Link

https://github.com/mattermost/mattermost-server/issues/21311

Release Note

NONE

[mm-cloud-bot]

@Tert0: Adding the "do-not-merge/release-note-label-needed" label because no release-note block was detected, please follow our release note process to remove it.

I understand the commands that are listed here

[mattermod]

Hello @Tert0,

Thanks for your pull request! A Core Committer will review your pull request soon. For code contributions, you can learn more about the review process here.

[mattermod]

E2E tests not automatically triggered, because PR has no approval yet. Please ask a developer to review and then try again to attach the QA label.

[furqanmlk]

/e2e-test

[mattermod]

Successfully triggered e2e testing! https://git.internal.mattermost.com/qa/cypress-ui-automation/-/pipelines/249389

[furqanmlk]

/update-branch

[mattermod]

This PR has been automatically labelled "stale" because it hasn't had recent activity. A core team member will check in on the status of the PR to help with questions. Thank you for your contribution!

[lieut-data]

Heads up that as part of our efforts to move to a monorepo, we're closing out a number of older pull requests like this one to help streamline the effort.

If you'd like to preserve these changes -- even if you're not the original author! -- feel free to resubmit the pull request against the monorepo once it's ready. You can subscribe to mattermost-server-issue-22420 for status updates on this effort.