CPS-43 Operating with Module Sets (groups of modules)

Addresses  CPS-43 - Getting issue details... STATUS

Problem description

Source files storage requirement

On initial model set upload all the uploaded files are expected to be treated as single package, where all the dependencies 
(imports and augmentations) are fulfilled. This allows to parse all the incoming files all together.

However the module set partial update process became complicated because of necessity to restore initial set of resource files
in order to fulfill missing dependencies. It make the source files persistence a requirement. Original files recovery also requires
extra interfaces to persistence service and extra logic to determine which file in the set requires to be replaced (if requires)

Standalone module vs module set

While we have clear dependencies of yang described module on context (surrounding modules) it's possible there could
be several modules within same dataspace having same namespace, name and revision, so these parameters are no
longer can be used as unique module identifiers. The actual module set (context) the is now important, while namespace
and revision became obsolete.

Solution proposal

To Discuss/ To Decide