[BUG] Importing a channel can delete recently added code templates

[mgaffigan]

Importing a channel that imports code templates will delete any code templates created since the client last loaded code templates.

Repro Steps

1. Create a channel xml that includes an exported code template
2. Open two clients (1 & 2)
3. In Client 1, create a new code template library and a template therein, save
4. In Client 2, without refreshing code templates, import the channel

Expected behavior
Either the template is imported, or an optimistic locking warning is displayed, but no code template libraries are deleted

Actual behavior
Code template created by Client 1 is deleted. No warnings are displayed.