Optimize deployment database updates

[PaulFarault]

When launching a deployment, we load all operations in memory and then update their status (at first the PLANNED status to PENDING in a loop, then operation result).

We may want to prevent this behavior and only retrieved the specific operations when needed (and create a dedicated query to update all PLANNED to PENDING and all PENDING on HELD in case of a failure).

Before, we should study what is loaded and when to see if this would really be an improvement.