Look for the study output both in folder and zip file for sensitivity analysis

[tbittar]

When launching sensitivity analysis with an output <my-output>, Xpansion looks for a zip file <my-output>.zip. In some workflows, the output may be decompressed, an the zip file may not exist. This causes Xpansion to crash as it does not find the output.

However, in such case, the folder <my-output> exists, therefore we also expect Xpansion to look for a normal folder in addition to the zip file. We may even look for the folder before the zip as if both exists, we should avoid decompressing the archive and work directly on the folder.