feat: add TagList overload to Metrics-Emit APIs as Attributes parameter

[Flash0ver]

Summary

Add an overload to all Metrics method groups (EmitCounter, EmitGauge, EmitDistribution) that accept Attributes, alongside the existing ReadOnlySpan<> and IEnumerable<> overloads.

Remarks

TODOs

• Move "EditorBrowsable Never" Attributes to separate PR
• Verify that we don't run into problems when adding conditionally-compiled non-public abstract methods to a type that is non-constructible by user code, e.g. when having a netstandard2.0 library with a PackageReference to Sentry that is referenced by a net8.0 application that also has a PackageReference to Sentry

[codecov]

Codecov Report

❌ Patch coverage is 56.66667% with 13 lines in your changes missing coverage. Please review.
✅ Project coverage is 74.19%. Comparing base (7deff34) to head (e08d695).

Files with missing lines	Patch %	Lines
src/Sentry/Internal/DefaultSentryMetricEmitter.cs	33.33%	4 Missing and 2 partials ⚠️
src/Sentry/Protocol/SentryAttributes.cs	71.42%	1 Missing and 1 partial ⚠️
src/Sentry/SentryMetricEmitter.Distribution.cs	50.00%	2 Missing ⚠️
src/Sentry/SentryMetricEmitter.Gauge.cs	50.00%	2 Missing ⚠️
src/Sentry/Internal/DisabledSentryMetricEmitter.cs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5241      +/-   ##
==========================================
+ Coverage   74.13%   74.19%   +0.06%     
==========================================
  Files         508      508              
  Lines       18282    18312      +30     
  Branches     3574     3580       +6     
==========================================
+ Hits        13553    13587      +34     
+ Misses       3860     3851       -9     
- Partials      869      874       +5     

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