DOC-2453: Port AI integration guides and gpt-4o upgrade into 6 Docs

[FarzadHayat]

Ticket: DOC-2453

Site: Staging branch

Port AI changes from 7 Docs to 6 Docs.

Changes:

• Update AI Assistant page
• Add AI live demo
• Add integration guides for OpenAI, Azure, Bedrock, Gemini
• Update to gpt-4o

Pre-checks:

• [x] Branch prefixed with feature/<version>/, hotfix/<version>/, staging/<version>/, or release/<version>/
• [x] modules/ROOT/nav.adoc has been updated (if applicable)
• [x] Files has been included where required (if applicable)
• [x] Files removed have been deleted, not just excluded from the build (if applicable)
• [x] Files added for New product features, and included a release note entry.

Review:

• [x] Documentation Team Lead has reviewed