[Rock-Ons] Add_storage affects all containers in a Rock-On

[FroggyFlox]

When one adds a share to an already-installed Rock-On through the webUI "Add Storage" function, all containers in the Rock-On are affected. See below for an example in which the share test_share01 was added to the Rock-On.
Before the modification, we have:

[root@rockdev ~]# docker inspect   --format "{{.Mounts}}" helloworld1
[{bind  /etc/localtime /etc/localtime  ro false rprivate}]

After we have:

[root@rockdev ~]# docker inspect   --format "{{.Mounts}}" helloworld1
[{bind  /etc/localtime /etc/localtime  ro false rprivate} {bind  /mnt2/test_share01 /test_volume01   true rprivate}]
[root@rockdev ~]# docker inspect   --format "{{.Mounts}}" helloworld2
[{bind  /mnt2/test_share01 /test_volume01   true rprivate} {bind  /etc/localtime /etc/localtime  ro false rprivate}]

The webUI now shows:

This is simply due to the fact that the feature is not container-aware so the update procedure goes through all containers with the given rockon.id.
Making this feature work at the container level rather than the Rock-on level could help customizing multi-containers Rock-On. This could be done in a similar way than in a (currently pending) PR: #1999.

Note that this simply is a refinement of an existing feature.

[phillxnet]

@FroggyFlox Nice find, and I agree that this would make for a valuable refinement in the style of your recent additions in this area. A tricky balance to keep between not over complicating a UI and providing adequate resolution of configuration.