[Feature]: Make analytics configurable and ask for consent  #63

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

Acceptance criteria

• The analytics id comes from configuration (none in development); depends on deciding whether to keep Google Analytics (with consent), replace it with something cookie-free, or remove it.

Steps to Reproduce

NA

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 F-07 of the viewer improvement plan. Size: S.