Track group coverage visits in vue instead

What does this MR do?

For #321191 (closed)

This MR moves the trigger for the usage ping i_testing_group_code_coverage_visit_total from the :show action in the controller to the mounted function in the Vue component.

The motivation for this is to track it in the same way as our other events so that the de-duplication of unique users can be done accurately so that we can group the metrics into an aggregated metric properly.

Screenshots

event request from devtools

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have included a changelog entry.
  • I have not included a changelog entry because this is not a user facing change and does not change the event name (which is already in the dictionary).
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Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done