UI test to change the language on personal setting page

[individual-it]

Description

this tests the "change language" feature on the personal setting page

Related Issue

https://github.com/owncloud/QA/blob/master/Server/Test_Plan_Settings.md

Motivation and Context

automate the manual testing for QA
This is build on top of #27860

How Has This Been Tested?

• run tests locally
• run tests in own fork

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[phil-davis]

Note: This PR is really just the last 2 commits. All the others are code from #27860 which was recently committed as 14252ec

[phil-davis]

I checked this the other day. Looks good to go.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.