fix: Support LogError calls with exception parameters for syntax highlighting

[willibrandon]

Description

LogError calls with exception parameters like logger.LogError(new Exception("error"), "User {UserId} failed", userId) were not getting syntax highlighting for the message template properties, while the exception constructor string was incorrectly being highlighted instead.

Root cause: The string literal parser in FindStringLiteral() was treating the first string literal found (exception constructor parameter) as the message template, instead of identifying that LogError with exception parameters has the actual message template as the second parameter.

Solution:

• Added IsLogErrorWithExceptionParameter() method that analyzes parameter structure by tracking parenthesis depth and comma positions to detect LogError patterns with exception parameters
• Enhanced FindStringLiteral() with skipFirstString parameter to skip the exception parameter and locate the actual message template
• Handles both string literal exception constructors (new Exception("literal")) and variable constructors (new Exception(variable)) through comma detection logic
• Added tests covering both LogError exception parameter scenarios

Type of change

• Bug fix
• New feature
• Performance improvement
• Documentation update

Checklist

• Tests pass (.\scripts\test.ps1)
• Benchmarks checked (if performance-related)
• Documentation updated (if needed)

Additional notes

Fixes #12

[Copilot]

Pull Request Overview

This PR fixes a syntax highlighting bug where LogError calls with exception parameters were incorrectly highlighting the exception constructor string instead of the actual message template. The fix adds logic to detect LogError patterns with exception parameters and skip the first string literal to find the correct message template.

• Added detection for LogError calls with exception parameters to distinguish them from regular LogError calls
• Enhanced string literal parsing to optionally skip the first string literal when an exception parameter is present
• Added comprehensive test coverage for both string literal and variable exception constructor scenarios

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
SerilogSyntax/Parsing/StringLiteralParser.cs	Enhanced FindStringLiteral method with skipFirstString parameter and logic to skip exception constructor strings
SerilogSyntax/Classification/SerilogClassifier.cs	Added IsLogErrorWithExceptionParameter method to detect exception parameter patterns and integrate with enhanced parser
SerilogSyntax.Tests/Classification/SerilogClassifierTests.cs	Added test cases for LogError with exception parameters using both string literals and variables
Example/ExampleService.cs	Added example code demonstrating LogError calls with exception parameters

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