Description of problem:

As for now, adding new hooks process is being done by adding them to hooks directory /usr/libexec/vdsm/hooks/ on the host.
This process can be painful for user, in a case of large number of hosts (user has to go host by host and create his hook).
In order to optimize the process, I would recommend about delegating the process to engine.
The idea is that user would be able to add his new hooks using engine.
For example, creating a new sub tab under cluster main tab in UI, where user will be able to upload his scripts and there he also would be able to add the hosts he would like them to contain the new hook.