hooks (pre/post) (deploy/undeploy/update/execute workflow...)

[fcdenos]

Is your feature request related to a problem? Please describe.
Currently, our plugin is using the yorc deployments path to store temporary files, signed script files downloaded from trusted server, etc., in order to avoid duplicating/re-downloading them for each operation in a deployment. (ex : we often have more than one component in a topology, which always exposes the same operations)

Describe the solution you'd like
Having pre/post (deployment/undeployment/update/execure workflow) hooks would allow us for example to manage a temporary directory at deployment scope, and more generally to manage deployment scope resources.
We could also use it (if the hook signature returns an error) to send a failure signal before any operation is done (by checking some pre conditions)
For example, if a needed service is not available, really starting the workflow in yorc could be useless)

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.