SQLTest healthcheck update to align with msqlserver:CU28-2019

[augustocristian]

This PR closes #104.
A recently cumulative update of msqlserver (sqldata container) broke up all the Dependabot updates in our CI system. We have changed the directory of the sqlcmd binary. Once updated, I've realized of some concurrency problems between our test cases, so I applied the same strategy than Fullteaching test suite.
The changes are:

• We have changed the location of sqlcmd binary to the newer ones
• We have changed the test output directories (one for each TJob)
• We have changed the background tasks dependencies to dont start and not saturate with requests the msql container
• Solved some flakiness due to timeouts of order-state changes

[javiertuya]

@augustocristian I ran this twice, the second one failed

[augustocristian]

I've executed 15 times since the new dependency of the two services, and no failure appear. I've also solved the flakiness related to the order change (I don't think that in the most elegant way)