Don't wait for jobs in SmartImportTests

[fedejeanne]

Remove calls to waitForJobs(...) in SmartImportTests and only join the (now correct) SmartImportJob instead.

Rename SmartImportWizard::getImportJob to createOrGetConfiguredImportJob and change its javadoc (the method was doing a lot more than simply retrieving a Job, which is what broke the tests in the first place).
Add a new method SmartImportWizard::getCurrentImportJob that merely returns the current job and join that job in the tests. Before this PR, a new job was being created and joined, which didn't make sense since that job was never started in the first place.

Fixes: #1427
Fixes: #1807

[github-actions]

Test Results

   921 files  ±0     921 suites  ±0   1h 10m 20s ⏱️ + 23m 41s
 7 514 tests ±0   7 362 ✅ +1  151 💤 ±0  1 ❌  - 1 
23 694 runs  ±0  23 186 ✅ +1  507 💤 ±0  1 ❌  - 1 

For more details on these failures, see this check.

Results for commit ffc46be. ± Comparison against base commit 016247d.

♻️ This comment has been updated with latest results.

[HeikoKlare]

Can you explain how removing the waiting for job completion is supposed to fix the referenced tests? In particular, the failure in #1807 seems to be because some project has not been imported, which is nothing I would expect to succeed after removing wait operations.

However, at least the first waitForBuilds() call in the tests seems to be obsolete, because the job is scheduled when finishing the wizard and thus the join() will block until the job has finished anyway.

[fedejeanne]

The wrong job was being joined, I changed the description of this PR to explain that.

[fedejeanne]

I'll squash the commits before merging, I'll let the tests run for now.