Make UniRetry & MultiRetry propagate the original Exception (#724)

[oliver-brm]

This changes the behavior of ExponentialBackoff#randomExponentialBackoffFunction so that the original Exception is propagated when the number of retries gets exhausted. An IllegalStateException with the number of retries made is added to the suppressed Exceptions in the original Exception.

[codecov]

Codecov Report

Merging #726 (8a28b71) into main (3a3e8c0) will increase coverage by 0.39%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##               main     #726      +/-   ##
============================================
+ Coverage     89.81%   90.20%   +0.39%     
- Complexity     2984     3001      +17     
============================================
  Files           374      374              
  Lines         11789    11790       +1     
  Branches       1478     1480       +2     
============================================
+ Hits          10588    10635      +47     
+ Misses          614      588      -26     
+ Partials        587      567      -20     

Impacted Files	Coverage Δ
...io/smallrye/mutiny/helpers/ExponentialBackoff.java	82.14% <100.00%> (+0.32%)	⬆️
...ye/mutiny/helpers/queues/SpscLinkedArrayQueue.java	97.61% <0.00%> (+0.79%)	⬆️
...a/io/smallrye/mutiny/helpers/BlockingIterable.java	89.79% <0.00%> (+1.02%)	⬆️
...mallrye/mutiny/operators/multi/MultiFlatMapOp.java	86.15% <0.00%> (+1.23%)	⬆️
...erators/multi/builders/SerializedMultiEmitter.java	82.27% <0.00%> (+1.26%)	⬆️
...subscription/SwitchableSubscriptionSubscriber.java	99.18% <0.00%> (+1.63%)	⬆️
...y/operators/multi/processors/UnicastProcessor.java	97.41% <0.00%> (+1.72%)	⬆️
...y/operators/multi/builders/IterableBasedMulti.java	84.04% <0.00%> (+2.12%)	⬆️
...mallrye/mutiny/operators/multi/FlatMapManager.java	98.61% <0.00%> (+2.77%)	⬆️
...operators/multi/builders/CollectionBasedMulti.java	96.77% <0.00%> (+3.22%)	⬆️
... and 5 more

[cescoffier]

Thanks!

I like the idea to add the suppressed exception, so we can know the last exception and the number of attempts.

[cescoffier]

@jponge I set the milestone to 1.2.0, but could be 1.1.2 as it can be seen as a bug fix.

[jponge]

It's actually going to be in 1.1.2 later today since it got merged to main 😉

[jponge]

(and we haven't done any branch, just doing commits along the way, fine here)