Replace Azure Pipelines with Gitlab CI

[esteve]

Removed Azure Pipelines and added Gitlab CI in preparation for the Gitlab migration.

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This change is 

[esteve]

@daggarwa I've readded Gitlab CI and also added a new job for cross compiling performance_test

[daggarwa]

@esteve Will this fail #90 if we merge in the Gitlab CI since its not currently containing any job to install Cyclone DDS whereas Azure did?

[daggarwa]

@esteve The CI pipeline is failing currently due to Cyclone DDS Mavin dependency. Can you please check what is the issue. Thanks

[daggarwa]

@esteve The CI pipeline is failing now due to $ cp LICENSE /opt/performance_test cp: cannot stat 'LICENSE': No such file or directory . I am not sure what is this error about.

[esteve]

@daggarwa Thanks. I'm working on it, but didn't have time to finish it yesterday.

[esteve]

@daggarwa I've fixed the last issue and the Gitlab CI now passes. I can't remove the Azure trigger until this PR has been merged, so it's fine the second check is still on hold.

[jpsamper2009]

Since we can't clear the status above (which refers to the old azure pipeline), I'll merge this manually.

[esteve]

@jpsamper2009 thanks!

@daggarwa we'll have to update the other PRs to use the new CI