Improve error message for invalid command buffer

`VUID-vkQueueSubmit-pCommandBuffers-00070` sometimes gives strange messages. The issue is we funnel everything from all objects into this check. Would be nice to spend time looking at it and see how to improve the message. (We have many tests for it already to use)

Locate the validation check for VUID-vkQueueSubmit-pCommandBuffers-00070 and review the existing tests for invalid command buffers. Identify how messages from different object types are funneled into this check, then use the existing tests to verify that the resulting messages are specific and no longer strange.

Written by the indexing model from the issue text.