Test: run the complete analyzer suite in syntax probes

[Jim8y]

Summary

• run all 32 built-in contract analyzers for every syntax probe
• keep analyzer errors visible alongside compiler diagnostics
• cover analyzer-only restrictions in the syntax compatibility matrix

Why

The probe harness only ran UnsupportedSyntaxAnalyzer. Unsupported APIs and type restrictions handled by other analyzers could therefore be missed by the compatibility suite.

Validation

• dotnet test tests/Neo.Compiler.CSharp.UnitTests/Neo.Compiler.CSharp.UnitTests.csproj --filter FullyQualifiedName~SyntaxTests --no-restore (139 passed)
• targeted dotnet format --verify-no-changes

Part of #1841.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.30%. Comparing base (487da8b) to head (78799f9).

Additional details and impacted files

@@            Coverage Diff             @@
##           master-n3    #1904   +/-   ##
==========================================
  Coverage      84.30%   84.30%           
==========================================
  Files            308      308           
  Lines          28370    28370           
  Branches        4005     4005           
==========================================
  Hits           23917    23917           
  Misses          3457     3457           
  Partials         996      996           

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[ajara87]

Suggested change

	.Select(type => (DiagnosticAnalyzer)Activator.CreateInstance(type)!)
	.Select(type =>
	{
	var instance = Activator.CreateInstance(type)
	?? throw new InvalidOperationException($"Could not instantiate analyzer {type.FullName}. Ensure it has a public parameterless constructor.");
	return (DiagnosticAnalyzer)instance;
	})

Activator.CreateInstance(type)! suppresses nullability warnings but it can still return null at runtime (e.g., no accessible parameterless constructor). Add an explicit null check and throw a clear error message