Support new type return by 'fsharp/documentation' and add support for "Open documentation" link from the tooltips

[MangelMaxime]

WHAT

🤖 Generated by Copilot at 42537c4

This pull request enhances the documentation feature of the extension by using a new type for documentation responses, enabling HTML rendering in the info panel, and simplifying the logic and rendering of the panel. The changes affect the LanguageService, DTO, and InfoPanel modules in the src folder.

🤖 Generated by Copilot at 42537c4

Sing, O Muse, of the valiant coder who refined the docs feature
With skillful changes to the DTO and the LanguageService modules
He stripped the Data field and made the Footer into FooterLines
Like Hephaestus who forged the shield of Achilles with cunning art

📝🛠️🌐

WHY

This PR adds support for ionide/FsAutoComplete#1099

HOW

🤖 Generated by Copilot at 42537c4

• Simplify the Panel.mapContent function to use the new DocumentationDescription type and avoid duplicate logic (link, link)
• Rename the Types field of the DocumentationDescription type to DeclaredTypes for clarity (link, link)
• Update the LanguageService.documentation and LanguageService.documentationForSymbol functions to use the new DocumentationDescription type and cast the response accordingly (link, link)
• Add the supportHtml option to the markdown settings in the LanguageService.private function to enable HTML rendering in the documentation panel (link)
• Check if the panel exists before updating it with the documentation link in the Panel.showDocumentation function (link)

[baronfel]

Merging this as we're getting ready for release!