workload/roachtest: implement --tolerate-retry-errors

[srosenberg]

A number of existing roachtests execute workload(s) with --tolerate-errors while at the same time incorrectly assuming that the workload(s) will do something useful. Since --tolerate-errors is indiscriminate wrt to the type of error, i.e., it ignores all of them, this implies that in the worst case, it's tantamount to assert true. Instead, most, if not all, of these roachtests could be strengthened to use --tolerate-retry-errors which would skip only the errors concerning transaction retries [1]; these are colloquially known as "ambiguous errors" [2].

[1] https://www.cockroachlabs.com/docs/stable/transaction-retry-error-reference
[2] #107571

Jira issue: CRDB-48005

[blathers-crl]

cc @cockroachdb/test-eng