Resolves #2590.

This PR:

• Removes the Navigation menu section. Explaining how to use the navigation menu felt like overkill – the UI should be intuitive enough not to need docs. Also, updating this section to account for the 9.2 changes while keeping it accurate for pre-9.2 versions would have made the section complex by adding more versioning tags, without necessarily adding much user value.
• Makes the wording around management and project settings sections more general, so it applies to all 9.x versions. Since some items are moving from Stack Management to a new Data management section, maintaining precise lists of menu items for both 9.2 and pre-9.2 versions and serverless would have introduced more versioning/tagging complexity. This also reduces maintenance complexity for future version updates.
• Reorders sections to reflect the order of pages in the 9.2 UI.
• Adds missing sections for attack discovery and notes.
• Updates any mention of items that have moved from Stack Management to Data management.
• Updates any screenshots that show the navigation menu.

Preview: Elastic Security UI