Delete obsolete classes ItemController
Revert "Delete obsolete classes ItemController"

This reverts commit 92e8d1474d813fc98ee6c3c730090f4e304a6e68.
Implement ItemController to create new Item
Create Item via ItemController
Implement listItems()
Show ListItemPane via ItemController
Add ItemController @Bean
@Inject ItemController instead of initialization
Use @Injected ApplicationContext rather than from
ClientApp.getApplicationContext()
Remove getApplicationContext()

static instance of ApplicationContext is not required as it can be
@Inject into @Bean
Merge branch 'develop'