Add TabNav navigate on click

[camelCaseChris]

Description

Changes proposed in this pull request:
This PR includes these features from #3197:

• If a TabNav child has category.navigateOnClick: true then the tab generated from that category can directly navigate to the path segment of that TabNav child. If several children have category.navigateOnClick: true for the same category label then the first child found will be used as the navigation target.

In addition, this PR includes the following:

• The TabNav component now uses the newer "icon-tab-bar" component from Fundamental Styles. The previous "tabs" component is deprecated and does not support multi-click areas.
• Other component and tests are adapted to the above change because e.g. they use selectors for classes that are now different.
• Fixes a likely bug in FD about a tab item with multi-click area making the button to expand the menu unusable when the link of that item has focus.

Other features descibed in #3197 are not included in this PR, e.g. supporting TabNav children that are hidden or using string values for category.navigateOnClick.

Related issue(s)
Implements part of #3197.