opencloud-eu/reva#655 changes the TUS create response for an invalid name
from 412 to 400. Update the invalid-name scenario to match.
Each example now carries its own expected status in an <http-status-code>
column. Names that fail ValidateName expect 400. The three folder/file rows
stay 412: filename() applies path.Base first, so "folder/file" becomes the
valid leaf "file" and never reaches the changed branch.
lowLevelCreationExtension.feature is unchanged; its missing-Upload-Length
case still returns 412.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>