Add option to specify paths for ScriptAnalyzer-evaluation

Summary of the new feature

This extension should include a setting to specify which paths to run Script Analysis against. Currently the extension reads the PSScriptAnalyzer.psd1-file in workspace root (if not modified) and executes PSSA against all files recursively.

Let's say you only want to run the rules against src/* and tool/*. AFAIK this can't be configured in the extension nor PSScriptAnalyzer.psd1, which can result in many unnecessary problems and warnings in folders without the same requirements to follow best practices.

Proposed technical implementation details (optional)

Invoke-ScriptAnalyzer solves this problem by requiring a Path or ScriptDefinition parameter. As the extension uses the latter option, then the logic and paths-setting would have to be part of the Script Analysis-part of vscode-powershell + PowerShellEditorServices.

Start by tracing the Script Analysis logic in vscode-powershell and PowerShellEditorServices, focusing on how Invoke-ScriptAnalyzer currently receives its ScriptDefinition and how PSScriptAnalyzer.psd1 is read. Define where a paths setting belongs, then verify that paths such as src/* and tool/* limit analysis while unrelated workspace files are excluded.