Invoke-Formatter is not idempotent on `--%` verbatim arguments

Steps to reproduce

Run the formatter repeatedly on a native command that uses the stop-parsing token:

$formatted = $null
1..3 | ForEach-Object {
    $formatted = Invoke-Formatter ($formatted ?? 'cmd --% raw | text & stuff')
    $formatted
}

Expected behavior

Formatting already formatted output should be a no-op. Spacing adjacent to the verbatim argument should either be left untouched or normalized once to a stable result.

Actual behavior

One additional space is inserted before | on every run:

cmd --% raw  | text & stuff
cmd --% raw   | text & stuff
cmd --% raw    | text & stuff

The output grows without bound in a format-on-save loop.

The verbatim-argument token owns the text up to the pipe. PSUseConsistentWhitespace with CheckPipe sees a zero-width gap before | and inserts a space inside the verbatim argument's extent on each formatting pass.

Environment data

Reproduced with:

• PSScriptAnalyzer 1.25.0 on PowerShell 7.5.2
• PSScriptAnalyzer 1.25.0 on PowerShell 7.6.3
• PSScriptAnalyzer built from main at PowerShell/PSScriptAnalyzer@4b0117ca7d2887711c9699f467ba7171f8859156 on PowerShell 7.6.4

首先，使用带有 --% stop-parsing token 的 native 命令重现重复的 Invoke-Formatter 示例。检查 PSUseConsistentWhitespace 在 verbatim-argument extent 附近对 CheckPipe 的处理；当重复格式化能够保持空格稳定，而不是在 | 前再插入一个空格时，即表示完成。