LayoutPanel: Switch to using the ToolsPanel

[andrewserong]

This issue is to propose / track progress on switching the LayoutPanel used by the layout block support over to using the ToolsPanel instead of PanelBody.

As new controls are added to the LayoutPanel, the area of the layout panel within the inspector controls increases, and there will likely be many blocks for which new controls should be hidden by default. As with the Typography (#33744) and Dimensions (#32392) panels previously, switching over to the ToolsPanel will allow blocks to define which layout controls to display by default.

For reference, here are screenshots of the Typography panel next to the Layout panel:

The group block's Typography panel (only font size is displayed by default)	Layout panel (all eligible controls displayed)

It's been mentioned a few times on other Github issues (e.g. recently by @jasmussen here: #35849 (comment)), so I thought this issue could be a useful place for looking at that task in isolation.

There are related earlier discussions about overhauling the panel and what gets included in it (e.g. #34698), however for the purposes of this issue, the task is to keep all the controls as-is for the moment, but refactor to the ToolsPanel so that in separate tasks, the decision of what goes where can be made.

[jasmussen]

Great ticket, thank you. One addition, when we move this to become a tools panel, we should hide by default the option to allow wrapping:

As a separate sidenote on the components (cc @ciampo), the justification icons should all be gray-900 (almost black). This is my bad, I included them in gray in a mockup, apologies. This is only for icons, to note, non active text items in a segmented control should still be dark gray.