Rule request: AvoidUsingBacktickLineTerminator

Summary of the new feature

As a code reviewer, I want script/module writers to receive automated informational warnings about backtick usage so that my review time isn't consumed by catching maintainability issues that tooling should prevent upfront.

Problem Statement:
The backtick (`) character is commonly used for line continuation in PowerShell, but it's considered poor practice for several reasons:

• Hard to see: Backticks are nearly invisible and easily missed during code review
• Poor readability: Makes code harder to read and understand
• Maintenance issues: Easy to accidentally remove or misplace during editing
• Non-intuitive: New PowerShell users often struggle with backtick usage

PowerShell offers better alternatives like parameter splatting and natural line breaks after operators/pipelines that are more readable and less error-prone.

Proposed technical implementation details

Rule Name: PSAvoidUsingBacktickLineTerminator

Severity: Information

Behavior:

• Flag any usage of backtick (`) character used for line continuation
• Suggest appropriate alternatives based on context

Recommended alternatives to suggest:

1. Parameter Splatting: For commands with multiple parameters
2. Natural line breaks: After pipeline operators (|), logical operators (-and, -or), comparison operators
3. Parentheses grouping: For complex expressions

Example violations:

# Backtick line continuation - Flagged
Get-Process -Name notepad `
    -ErrorAction SilentlyContinue `
    | Where-Object CPU -gt 100

# Complex command with backticks - Flagged  
$result = Get-ChildItem -Path C:\Temp `
    -Filter "*.txt" `
    -Recurse `
    -ErrorAction SilentlyContinue

Technical Implementation:

• I plan on taking this issue if approved.
• Simple class that inherits ITokenRule:

public IEnumerable<DiagnosticRecord> AnalyzeTokens(Token[] tokens, string fileName)
{
    if (tokens == null) throw new ArgumentNullException(Strings.NullTokensErrorMessage);

    var lineContinuationTokens = tokens.Where(token => token.Kind == TokenKind.LineContinuation);

    foreach (var tokenNode in lineContinuationTokens)
    {
        yield return new DiagnosticRecord(
            string.Format(CultureInfo.CurrentCulture, Strings.AvoidUsingBacktickLineTerminatorError),
            tokenNode.Extent,
            GetName(),
            DiagnosticSeverity.Information,
            fileName
        );
    }
}

What is the latest version of PSScriptAnalyzer at the point of writing

1.24.0

先檢查現有的 ITokenRule 實作，以及 issue 中描述的 AnalyzeTokens 進入點，尤其是 TokenKind.LineContinuation 和 Strings 中的診斷訊息。確認類似規則是如何註冊和測試的。完成的標準是：反引號行延續 token 會產生包含規則名稱和來源範圍的資訊診斷，同時不會標記不相關的 token。