Add tooltip to sidebar title menu item

Proposal

Add a tooltip to the sidebar title menu item when menu is collapsed. Originally raised #322687 (comment 596189752).

Also if the text is too long then a tooltip should reveal the name even when the menu is expanded. Originally commented here #332988 (comment 601817368)

The value should be equal to the text value that is in the span sidebar-context-title. The rationale for this is that this makes it consistent for all sidebars.

• Group
• Admin
• Security
• User Settings

Testing

Please run package-and-qa and assign a SET to MR for verification. Test coverage at component/system level would be sufficient.