Fix T56372: Properly show error messages when submission fails

This also introduces a word-wrapping function that takes variable character
widths into account.

benchmark/submission/__init__.py

@@ -1,3 +1,6 @@
+from .client import CommunicationError
+
+
 def submit_benchmark(benchmark_data: dict):
     """Submit benchmark data to MyData.
 
@@ -8,7 +11,7 @@ def submit_benchmark(benchmark_data: dict):
     import logging
     import os
 
-    from .client import CommunicationError, BenchmarkClient
+    from .client import BenchmarkClient
 
     mydata_url = os.environ.get('MYDATA') or 'https://mydata.blender.org/'
     if 'MYDATA' in os.environ: