If driver returns error code that we do not know, we simply output
"unknown vulkan error code". Instead we should at least include the
actual errorCode here so that people can search up to see what it is.

Also remove the double period at the end of string and added a few other
vulkan error strings.

Bug: b/154665382
Change-Id: Ic4138e90534b4e7d97520fe10ac1477d2930d9c8
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2160130
Commit-Queue: Charlie Lao <cclao@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Tim Van Patten <timvp@google.com>