Add option to build all plugins in SuperBuild

[errollgarner]

• CI build now builds all plugins

[hgueziri]

When the option is turned on then off, cmake should reset to default plugin:

• ContourSurface
• LabelVolumeToSurface
• LandmarkRegistration
• USAcquisition

[errollgarner]

@hgueziri, the solution in this last commit has the required behaviour. I think it is overall a better solution as it doesn't affect the state of the cache. So setting build_all to on then off from any set of selected plugins (not just defaults) will result in exactly that set being selected afterwards. The only downside is that it requires modules that have dependencies to not only check if their dependencies are selected, but actively set them on (as was the case for PedicleScrewNavigation) when they weren't already.

[errollgarner]

Worthy of note: this explicit activation of dependencies doesn't affect the cache and is therefore not persistent upon deselection of the build_all option.