[BUGFIX] Render only one toggle per node in trees

In non-SVG trees, there are currently two icons representing the node's
expansion state rendered that get toggled via CSS rules based on
hard-coded aria attributes and icon identifiers, which is a bad
practice.

To solve this, a new web component `typo3-backend-tree-node-toggle` is
added whose only responsibility is to render the correct icon based on
its `aria-expanded` attribute

Resolves: #100549
Releases: main, 12.4
Change-Id: I1a955731fc21da01a914b1ef721d7eb2d1e18ed5
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/79826


Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>