Introduce Outcome

[martintmk]

Details on the issue fix or feature implementation

Contributes to #1328

Confirm the following

• I started this PR by branching from the head of the default branch
• I have targeted the PR to merge into the default branch
• I have included unit tests for the issue/feature
• I have successfully run a local build

[codecov]

Codecov Report

Merging #1331 (1ffeac8) into main (af39ebe) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #1331      +/-   ##
==========================================
- Coverage   83.54%   83.53%   -0.01%     
==========================================
  Files         268      269       +1     
  Lines        6400     6397       -3     
  Branches     1003     1003              
==========================================
- Hits         5347     5344       -3     
  Misses        844      844              
  Partials      209      209              

Flag	Coverage Δ
linux	?
macos	83.53% <100.00%> (-0.01%)	⬇️
windows	83.53% <100.00%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...rc/Polly.Core/Timeout/TimeoutResilienceStrategy.cs	100.00% <ø> (ø)
src/Polly.Core/VoidResult.cs	100.00% <ø> (ø)
...ircuitBreaker/Controller/CircuitStateController.cs	100.00% <100.00%> (ø)
.../Polly.Core/Fallback/FallbackResilienceStrategy.cs	100.00% <100.00%> (ø)
src/Polly.Core/Hedging/Controller/TaskExecution.cs	100.00% <100.00%> (ø)
...rc/Polly.Core/Hedging/HedgingResilienceStrategy.cs	100.00% <100.00%> (ø)
src/Polly.Core/Outcome.TResult.cs	100.00% <100.00%> (ø)
src/Polly.Core/Outcome.cs	100.00% <100.00%> (ø)
...c/Polly.Core/ResilienceStrategy.Async.ValueTask.cs	100.00% <100.00%> (ø)
.../Polly.Core/ResilienceStrategy.Async.ValueTaskT.cs	100.00% <100.00%> (ø)
... and 8 more