Fixes #9631

UI tests: Segment editor improvements https://github.com/piwik/piwik/issues/6766 - Consistent naming in Manage users https://github.com/piwik/piwik/issues/9373

As a Super User:

 * I can now see all segments that were created for this website by any other user
 * When a segment was created by another user who is not Super User, the segment appears below a new section "Visible to you because you have Super User access:"
 * Such segments are editable by the Super User
 * The only difference when editing someone else's segment, as a Super User, is that "This segment is visible to [ME]" now says "This segment is visible to [SEGMENT_AUTHOR_USERNAME]"
 * One can now search in the  search bar for a username and see all segments created by this user

For all users:

 * New section "Shared with you:" now lists segments created by a Super User, and marked as "Visible to [All Users]"
 * Before segments  shared with me, looked the same as segments I created, which was confusing

UI tests: Contrast for close button https://github.com/piwik/piwik/pull/9572  https://github.com/piwik/piwik/issues/9155

UI tests: Added new config file viewer https://github.com/piwik/piwik/pull/9526 + better visitor profile https://github.com/piwik/piwik/pull/9502

add possibility to view config values, including description, default value and whether it is an adjusted config value in the ui

refs https://github.com/piwik/plugin-QueuedTracking/issues/21 allow any plugin setting to be overwritten in the config file

Use Request::processRequest instead of using API::updateSite directly so excessive sanitization is used and site name is stored properly in OmniFixture DB.

When generating the OmniFixture dump, restore site properties to their initial values before setting up each initial fixture. Ensures that changes to site properties by fixtures are reset before setting up the next fixture.

Archive in UITestFixture using correct test environment overrides (loadRealTranslations=1 is needed for archiving) so results are accurate. Also, do not use Fixture::getTestEnvironment() in fixtures, instead create new instances of TestingEnvironmentVariables so changes made to the file are not ignored/lost.

Remove change to site settings in InvalidVisits.php after it is no longer needed so when fixtures are setup together, the change won't carry over into other fixtures.