PIM UI - Validation following PF3 style

Currently PIM UI doesn't have any sort of validation. The following checks are needed:

• Plans
  • name must not be empty
  • Source and target process definitions must be different
  • One node cannot be mapped more than once
  • Source and target nodes must be of the same type
• Migrations
  • CallbackURL must be a valid URL
  • ScheduledStartTime must be a future valid date