[META] Grouped navigation menu

[jmikell821]

Issue: elastic/kibana#136732
PR: elastic/kibana#136819

In 8.3, grouped navigation was an option in advanced settings. In 8.4, this setting will be enabled by default.

To do:

• Remove the grouped navigation topic from the TOC, but move contents into Elastic Security UI topic.
• Update Elastic Security UI topic to remove old content and include new nav updates.
• Track and update all topics, including images, that require menu changes. See Google spreadsheet.
• Update advanced settings topic that mentions grouped navigation to "Disable grouped navigation" since it'll be enabled by default.

Old nav:

New nav:

Note: Users can still disable the navigation at Stack Management > Advanced Settings > Security Solution > New streamlined navigation.