[5.8] Provide retry callback with the attempt count

[AJenbo]

This provides the call back with a attempt count, this can be helpful for function that need to modify there behavior with each attempt, or log it some how. Existing code should be unaffected since there was not parameter earlier.

[BrandonSurowiec]

This method was written using goto for a very specific reason.

Check out this PR that contains links to threads about it: #15973

(Also, this PR would need tests.)

[AJenbo]

Thanks for the quick review. I have rewritten the code so that it keeps the goto and added a test for retry that tests this and the existing features.

I would add that the goto feel like an micro-optimization (is it true for 7.2, will it be true for 8.0?), with the addition of $attempt++ this would also mean that it saves a jump or two at the cost of an additional $times--, also the php code is 7 lines longer.