CndImportDialog can directly use BootstrapUtils.initializeNodetypes instead of indirectly via a temporary 'bootstrap' initialize item

For importing a CND via the (Console) CndImportDialog the current implementation delegates to the bootstrap InitializationProcessor, creating a temporary initialize item to trigger the process.
In the end, the BootstrapInitializationProcessor delegates this task further to BootstrapUtils.initializeNodetypes.
Which the CndImportDialog just as well can invoke directly itself (no additional context or parameters needed).

So this is just a simple improvement, cutting out the intermediate processing via the bootstrap InitializationProcessor.