Convert records to classes

[martintmk]

Details on the issue fix or feature implementation

These records expose unnecessary APIs that we do not want to rely on in the future if it's not used by anything.

Contributes to #1365

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 #1422 (5bc7531) into main (7f6b8a4) will increase coverage by 0.17%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #1422      +/-   ##
==========================================
+ Coverage   83.74%   83.92%   +0.17%     
==========================================
  Files         276      275       -1     
  Lines        6454     6526      +72     
  Branches     1007     1007              
==========================================
+ Hits         5405     5477      +72     
  Misses        840      840              
  Partials      209      209              

Flag	Coverage Δ
linux	?
macos	83.92% <100.00%> (+0.17%)	⬆️
windows	83.92% <100.00%> (+0.17%)	⬆️

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

Impacted Files	Coverage Δ
...lly.Core/Telemetry/TelemetryEventArguments.Pool.cs	100.00% <ø> (ø)
...rc/Polly.Core/Telemetry/TelemetryEventArguments.cs	100.00% <ø> (ø)
...CircuitBreaker/CircuitBreakerResilienceStrategy.cs	100.00% <100.00%> (ø)
...ircuitBreaker/Controller/CircuitStateController.cs	100.00% <100.00%> (ø)
...ly.Core/CircuitBreaker/OnCircuitClosedArguments.cs	100.00% <100.00%> (ø)
...ore/CircuitBreaker/OnCircuitHalfOpenedArguments.cs	100.00% <100.00%> (ø)
...ly.Core/CircuitBreaker/OnCircuitOpenedArguments.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)
...ly.Core/Hedging/HedgingActionGeneratorArguments.cs	100.00% <100.00%> (ø)
... and 14 more