max_tries argument for retries

[daniel-sanche]

Currently, retries only expire due to time-based timeout. In some cases, it is useful to have an attempt-based expiration option (for example, for datastore).

We could add a max_tries argument to our retry functions, and set it to None by default. But allow users to override it

This feature would have implications for #530, which would have to expose an additional failure reason instead of the bool is_timeout

[ohmayr]

Closing this since we have the following issue: #535