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.

Tests show that processing minimum event value  works correctly
Fixed tests in plugins/AnonymousPiwikUsageMeasurement

fixes #9194 fix "goal can be only converted once per visit" is not respected when segmenting goals with a log_link_visit_action segment

fix error table log_visit is already joined in https://github.com/piwik/plugin-CustomDimensions/pull/19

This reverts commit 745c6c6d.