Importing a channel should show a conflict when the ID already exists

[rbeckman-nextgen]

Right now you will only see a conflict warning if the channel name already exists, but not if the ID exists. This means that if you have the same channel on your dev and prod boxes, change the name on the dev box, and then re-import it into prod, it will actually be imported as a completely new channel, rather than overwriting the existing channel. Overwriting shouldn't happen automatically, but users should at least have the option.

Imported Issue. Original Details:
Jira Issue Key: MIRTH-3895
Reporter: narupley
Created: 2016-02-26T08:05:59.000-0800