misba.abbas@mongodb.com provided some design feedback on the initial implementation of the rename collection flow.

1. Disable the "Proceed to rename" button when the user enters the name of a collection that already exists in the current database and display an error with the following text:

   This collection name already exists in this database

2. (follow up to 1.) On the off-chance that a collection is created in the background / from another connection and Compass doesn't have knowledge of it, the user could conceivably attempt to rename a collection to an existing collection that Compass has no knowledge of.  We should handle the "target namespace exists" error that the server returns and display the same error text as 1.  
3. Disable the `Proceed to rename` button if the user has not entered anything (if the collection name is "")
4. Clear any existing errors after the user modifies their new collection name
   1. Currently, if the user enters a collection name, attempts to rename, receives an error and then modifies the collection name, the error persists.  The error should be cleared as soon as the user modifies the collection name.