Run the integration test import twice for better test case coverage

## Is your feature request related to a problem? Please describe
It would be good to have a second import of the solution (before it's uninstalled) to test additional test cases. These include:
- Ensure the solution within the package are detected and therefore the processes are enabled (please see #59)
- To hook up a custom connection reference which is first installed in the first install (please see #55)

## Describe the solution you'd like
More test cases and refactoring of the test fixture to call the import a second time

## Additional Context
> We can only test the failing circumstances if we did two deployment rounds. This would make #58 testable too. What are your thoughts?

Yep, we've run into this issue a few times. I wonder if we can have a second test fixture that we can order to only run after the first test fixture?

_Originally posted by @ewingjm in https://github.com/Capgemini/powerapps-packagedeployer-template/issues/59#issuecomment-828357622_

Start by locating the integration test fixture and its solution import and uninstall flow. Review related issues #55, #58, and #59 for the connection reference, failing circumstances, and package detection cases; done means a second import runs before uninstall and exercises the additional cases.

Written by the indexing model from the issue text.