Avoid to add vim info with ESR if the vim is already provisionned

Avoid to add vim info with ESR if the vim is already provisionned

- Optimization of the cloud configuration
- CloudRegionCreateStep was called twice
- Change the name of RegisterCloudRegionToMulticloud to RegisterCloudRegion
to be more generic
- Having the cloud creation in RegisterCloudRegionStep avoid adding the ESR
each time an instantiation is launched so the CloudRegionCreateStep is now
inserted in RegisterCloudRegionStep
- USE_MULTICLOUD was no longer checked
- The adding of availability zone and tenant is also moved to RegisterCloudRegionStep
Pylint issue corrected
Minor errors (init without added step)
Issue-ID: TEST-264
Signed-off-by: Thierry Hardy <thierry.hardy@orange.com>
Change-Id: Ibfd5506412fd7472144165c19bfe9e4dc53d6e08
Signed-off-by: Thierry Hardy <thierry.hardy@orange.com>