Return failed status and code 400 for unsuccessful requests about ditto HOT 2 CLOSED

Remember to add the relevant status and status code checks to the system tests when fixing these requests

from ditto.

Testing:

• listpresent for a bucket that does not exist returns a fail status and a 404 status code
• copydir, copynew, and copyupdate all return a 404 if the directory or bucket do not exist
• deletefile returns a 404 if the bucket or file does not exist
• createbucket returns a 400 if the bucket name is invalid or the bucket already exists

from ditto.