v6.0: Rationalise Execute()/ExecuteAsync() overloads

[reisenberger]

Polly historically includes a large number of .Execute(...) or .ExecuteAsync(...) overloads, 20-40 per policy type (sync vs async, non-generic vs generic). There are then a comparable number of ExecuteAndCapture(...) overloads.

Polly v6.0 proposes rationalising the number of execute overloads by removing some anomalous cases. Certain overloads dating back several years take an input parameter, for example Context, but do not pass this parameter to the delegate to execute (example). This defies expectations in not providing a pattern where the input parameters passed to the overload match the input parameters taken by the executed delegate. (Why do they exist? They date from pre- current maintainers and could have obscure uses in passing the Context to an onRetry policy hook but not the delegate.)

Polly v6.0 proposes rationalising the .Execute/Async/AndCapture() overloads by removing these and a few other minor variants.

All affected overloads have already been omitted from the Polly execution interfaces available since Polly v5.2.0, ie for the last 8 releases / 9 months. Those already using the interfaces will experience no change.

v5.9.0 will pre-advertise the deprecations with [ObsoleteAttribute()], per semver. v6.0 would push through the changes as breaking changes.

EDITED: to pin linked example by linking to specific commit.

[reisenberger]

Polly v5.9.0 has now been published. It deprecates the overloads scheduled for removal (example).

Polly v6.0 will removed the deprecated overloads entirely.

[reisenberger]

Documentation published to wiki