validate_backend

Validate that a string looks like an acceptable Backend value.

Note that this is not meant to be a filter for things that could cause security issues, it is only meant to catch errors before the hostcalls do in order to yield friendlier error messages.

This function will return a BackendError if an invalid name was given.

Backend names:

• cannot be empty
• cannot be longer than 255 characters
• cannot ASCII control characters such as '\n' or DELETE.
• cannot contain special Unicode characters
• should only contain visible ASCII characters or spaces