Remove .NET Framework remarks (System.Windows)

[gewarren]

.NET Framework API ref has moved to its own repo (https://github.com/dotnet/dotnetfw-api-docs), so we can clean up .NET Framework remarks, exceptions, and code examples out of this repo. Contributes to #12513.

Removes remarks and examples related to:

• .NET Framework versions
• Code-access security
• Configuring apps via app.config file
• App domains

Also removes all remarks from obsolete APIs.

Hide whitespace changes

[Copilot]

Pull request overview

This PR updates the WPF (System.Windows) ECMA XML reference docs to remove or tone down .NET Framework-specific remarks and wording, aligning this repo with the split to dotnetfw-api-docs.

Changes:

• Removes .NET Framework version/configuration guidance (for example, app.config/AppContext note) from affected remarks.
• Rewords several remarks/summaries to drop “.NET Framework” phrasing (for example, “supports the .NET infrastructure”).
• Normalizes some markdown formatting in <format type="text/markdown"> blocks (whitespace/line layout).

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
xml/System.Windows/FrameworkElement.xml	Removes a .NET Framework-specific layout rounding note; updates markdown content in remarks.
xml/System.Windows/AttachedPropertyBrowsableForChildrenAttribute.xml	Rewords remarks to remove “.NET Framework attribute” phrasing.
xml/System.Windows/AttachedPropertyBrowsableAttribute.xml	Rewords/normalizes the remarks markdown and removes .NET Framework-specific phrasing.
xml/System.Windows/Application.xml	Removes a .NET Framework version-introduction note from ResourceAssembly remarks.
xml/System.Windows.Documents/PageContentCollection.xml	Updates internal infrastructure wording in the IEnumerable.GetEnumerator summary.
xml/System.Windows.Documents.DocumentStructures/TableStructure.xml	Normalizes remarks markdown formatting and updates internal infrastructure wording.
xml/System.Windows.Documents.DocumentStructures/TableRowStructure.xml	Normalizes remarks markdown formatting and updates internal infrastructure wording.
xml/System.Windows.Documents.DocumentStructures/TableRowGroupStructure.xml	Normalizes remarks markdown formatting and updates internal infrastructure wording.
xml/System.Windows.Documents.DocumentStructures/StoryFragment.xml	Updates internal infrastructure wording in an AddChild-style member summary.
xml/System.Windows.Documents.DocumentStructures/ParagraphStructure.xml	Normalizes remarks markdown formatting and updates internal infrastructure wording.
xml/System.Windows.Documents.DocumentStructures/ListStructure.xml	Normalizes remarks markdown formatting and updates internal infrastructure wording.
xml/System.Windows.Documents.DocumentStructures/FigureStructure.xml	Normalizes remarks markdown formatting and updates internal infrastructure wording.
xml/System.Windows.Diagnostics/ResourceDictionaryDiagnostics.xml	Rewords remarks to remove “.NET Framework infrastructure” phrasing; normalizes markdown formatting.