Site Editor: Move the Page and Template Selectors into the new Navigation

[Copons]

The new Navigation component has been merged.

Let's move the page/template selector away from the site editor header and into the new navigation!

gutenberg/packages/edit-site/src/components/header/index.js

Lines 108 to 127 in 668a710

	<div className="edit-site-header__toolbar-switchers">
	<PageSwitcher
	showOnFront={ showOnFront }
	activePage={ page }
	onActivePageChange={ setPage }
	/>
	<div className="edit-site-header__toolbar-switchers-separator">
	/
	</div>
	<TemplateSwitcher
	page={ page }
	activeId={ templateId }
	activeTemplatePartId={ templatePartId }
	isTemplatePart={ templateType === 'wp_template_part' }
	onActiveIdChange={ setTemplate }
	onActiveTemplatePartIdChange={ setTemplatePart }
	onAddTemplate={ addTemplate }
	onRemoveTemplate={ removeTemplate }
	/>
	</div>

See #25260, #25261

[Copons]

Fixed by #25620 and #25615!