[Feature]: Requirement details panel  #70

What type of issue is this?

• Bug report
• Feature request

Prerequisites

• I have written a descriptive issue title
• I have verified that I am running the latest version of the reqifviewer
• I have searched open and closed issues to ensure it has not already been reported

Description

Today the details of a requirement start with ReqIF metadata ("Long Name: NOT SET", "Description: NOT SET", identifier) and show the text as one row in an attribute grid; traces and pictures are at the bottom of the page.

Acceptance criteria

• Opens as a side sheet from any view (and as a page for deep links): text first; then attributes as a definition list (empty ones hidden behind a toggle); incoming and outgoing traces grouped by relation type; the specifications it appears in; its attachments.
• ReqIF details (identifier, type, last change, alternative id) are in a collapsed "ReqIF details" section.
• Previous and next requirement navigation within the specification.

Steps to Reproduce

Load requirements-and-objects.reqifz or ProR_Traceability-Template-v1.0.reqif (reqifviewer.Tests/TestData) and look at the pages mentioned above.

System Configuration

• reqifviewer version: 6.1.0 (development, with [Refactor] Blazor Blueprint app shell and Blazor Web App hosting #56)
• Environment (Operating system, version and so on): Windows 11, Chrome
• .NET Framework version: .NET 10
• Additional information: Plan item R-04 of the viewer improvement plan. Size: M. Depends on: [Feature]: Readable labels for requirements: detect the id and text attributes  #68.