chore: common linq loop allocations, add small optimisations

[TimothyMakkison]

Remove linq allocations, add small optimisations

Description

Slightly microbenchmarky improvements, not sure about the manual foreach loops

• Remove FirstOrDefault allocation from SymbolExtensions.ImplementsGeneric - 106KB - Func<INamedTypeSymbol, Boolean>
• Remove Where allocation from SymbolAccessor.GetMappableMembers - 76KB - Func<ISymbol, Boolean>
• Remove Where allocation from SymbolAccessor.GetAttributes - 150KB - Func<AttributeData, Boolean>
• Use non string comparison NonNullableValueType check
• Add IsRefLike check to GetEnumeratedType
• Remove unneeded types.Get<int>() call from CollectionInfoBuilder.FindCountProperty

Related to #530

Benchmarks

200 KB saved, little change in speed.

Method	Mean	Error	StdDev	Gen0	Gen1	Allocated
Compile	1.441 ms	0.0206 ms	0.0237 ms	78.1250	15.6250	162.41 KB
LargeCompile	56.606 ms	1.1015 ms	1.4323 ms	1428.5714	428.5714	9367.77 KB

Original

Method	Mean	Error	StdDev	Gen0	Gen1	Allocated
Compile	1.450 ms	0.0288 ms	0.0374 ms	78.1250	19.5313	167.37 KB
LargeCompile	55.899 ms	1.0530 ms	1.3318 ms	1428.5714	428.5714	9579.64 KB

Changes

Checklist

• The existing code style is followed
• The commit message follows our guidelines
• Performed a self-review of my code
• Hard-to-understand areas of my code are commented

[codecov]

Codecov Report

Merging #555 (1f0c659) into main (85347e4) will decrease coverage by 0.27%.
The diff coverage is 91.17%.

❗ Current head 1f0c659 differs from pull request most recent head 8443d3d. Consider uploading reports for the commit 8443d3d to get more accurate results

@@            Coverage Diff             @@
##             main     #555      +/-   ##
==========================================
- Coverage   91.96%   91.70%   -0.27%     
==========================================
  Files         147      158      +11     
  Lines        4656     5448     +792     
  Branches      588      698     +110     
==========================================
+ Hits         4282     4996     +714     
- Misses        254      306      +52     
- Partials      120      146      +26     

Impacted Files	Coverage Δ
.../Riok.Mapperly/Helpers/NullableSymbolExtensions.cs	92.98% <0.00%> (-2.02%)	⬇️
...numerables/EnsureCapacity/EnsureCapacityBuilder.cs	45.94% <42.10%> (-32.32%)	⬇️
...ok.Mapperly/Configuration/AttributeDataAccessor.cs	68.88% <64.58%> (-7.93%)	⬇️
...lders/NewInstanceObjectMemberMappingBodyBuilder.cs	79.58% <78.94%> (+0.79%)	⬆️
.../Descriptors/MappingBuilders/SpanMappingBuilder.cs	80.00% <80.00%> (ø)
...iptors/MappingBuilders/DictionaryMappingBuilder.cs	90.98% <85.00%> (+4.02%)	⬆️
...scriptors/InlineExpressionMappingBuilderContext.cs	95.91% <85.71%> (+0.79%)	⬆️
...Mapperly/Descriptors/UserMethodMappingExtractor.cs	93.77% <85.71%> (+0.08%)	⬆️
...escriptors/MappingBuilders/MemoryMappingBuilder.cs	88.46% <88.46%> (ø)
...rc/Riok.Mapperly/Configuration/StringMemberPath.cs	88.88% <88.88%> (ø)
... and 46 more

... and 2 files with indirect coverage changes

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[github-actions]

🎉 This PR is included in version 2.9.0-next.3 🎉

The release is available on:

• GitHub release
• v2.9.0-next.3

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[github-actions]

🎉 This PR is included in version 3.0.0 🎉

The release is available on:

• GitHub release
• v3.0.0

Your semantic-release bot 📦🚀