[Feature Request] Add some kind of extra on some logs for easier identification

[cretz]

Describe the solution you'd like

Some users in their custom log handlers want to identify certain log records so they can do something else with them (e.g. increase/decrease the log level). We need some kind of clear string they can use as a conditional instead of checking English message patrterns. Research the best way to provide this (e.g. on extra?). This only needs to be logging done on activity failures and workflow task failures at this time, but may be able to apply to other warning logs or similar situations.

Also a sample showing how to customize log level for workflow task failure would be helpful here once this issue is done.