Request level retry strategy support

[NeoCN]

Is there plan to support request level retry strategy? Currently request will use client retry strategy, and can not override at request level.

[jeevatkm]

FYI, yes - #315 (comment)

[jeevatkm]

@NeoCN I thought to inform you. RetryConditions at the request level enhancement PR #436 got submitted by @rohitkg98. Will close this one after the merge.