Custom exception types for amended query job exceptions

[tswast]

I noticed in googleapis/python-bigquery#1105 that we turn off type checking to add query_job and now debug_message properties to a GoogleAPICallError.

It'd be great if (a) there were some generic debug properties we could add to on the core GoogleAPICallError and/or (b) we had a custom exception type(s) so that folks can more easily discover debug_message and query_job.

[parthea]

Transferring to google-cloud-python as the code for python-bigquery will be migrated there in 1-3 weeks.

[parthea]

Transferring this issue back to python-bigquery.

[chalmerlowe]

This issue was moved from the following repo as part of the monorepo migration: googleapis/python-bigquery