PSAvoidTrailingWhitespace should ignore empty lines indented to match the current block

Currently, PSAvoidTrailingWhitespace checks all lines for trailing whitespace, even when that line is effectively empty and the "trailing" whitespace is actually leading whitespace for the current indentation level. If the recommended action is taken (remove the whitespace), then adding new code in those spots requires re-indenting that spot to the current code indentation level.

I propose that it should respect the current indentation level for an empty line and not generate a note for those lines, as long as they match the indentation of the current block of code.

What is the latest version of PSScriptAnalyzer at the point of writing
1.17.1, shipping with the vscode-powershell extension version 1.8.1

首先找到 PSAvoidTrailingWhitespace 规则的实现及其现有测试。复现一个缩进到当前块级别的空行案例，然后验证匹配的缩进会被忽略，而实际存在的尾随空白仍会被报告。完成的标准是该行为有测试覆盖，并且规则能够区分这些情况。