Use a proper tooltip for the Metadata Quality widget

[jahow]

Description

The Metadata Quality widget currently shows a popover with details on how the quality indicator is computed:

This popover is not a "real" popover in that it isn't showing on top of everything else, but simply appended to its parent element. This has been shown to produce issues when this component is used in other contexts, e.g. having scrollbars show up etc. (this can notably be the case for custom apps)

An improvement would be to use a shared popover component in the project, which would give:

• no unexpected layout issues
• better "standardized" styling for the popover
• less code in the actual metadata-quality component

Motivation

Issues were encountered in the MEL custom app worked on by Camptocamp.

Inspiration and context

The tippy library is great for handling popovers and is already used in the project for the "favorite star" tooltip:

This library should probably be encapsulated in a shared ui-layout component which would be used both by the favorite star toggle and the metadata quality widget.