Update docs for Open edX as LTI consumer for Verawood release

[ayub02]

This PR updates and reorganizes the Open edX documentation for using the platform as an LTI consumer.

• Added a conceptual overview of the LTI Consumer component and configuration options.
• Updated the setup guides for LTI 1.1/1.2 and LTI 1.3 tools.
• Documented reusable LTI configurations managed through LTI Store.
• Added reference documentation for LTI Advantage services.
• Expanded educator and site operator guidance for sharing personally identifiable information with LTI tools.
• Added instructions for enabling reusable configurations and per-XBlock launch URLs.
• Added and updated screenshots for the current Studio and Django Admin interfaces.
• Updated navigation, release notes, and cross-references.
• Added redirects for deleted or moved LTI documentation pages.
• Removed the LTI enablement and component settings pages.

[sarina]

@ayub02 - I'm not going to make a blocking review here as I'm on PTO the next two weeks, but please do address all my comments.

If you could kindly find a subject matter expert to do a final review, then Feanil can merge for you.