Move enableComplementaryArea call to Sidebar

It makes more sense, i believe, to enable the sidebar complementary
area from within the sidebar component, as this is called when the
component is included in the hierarchy.

I also moved the scope string to a constants file, so i can find where
it is used with code analysis instead of relaying on grep.

editor/BlockEditor.jsx

@@ -1,9 +1,9 @@
-import { useSelect, useDispatch } from '@wordpress/data';
-import { useEffect } from '@wordpress/element';
-import { InterfaceSkeleton, FullscreenMode, ComplementaryArea, store as interfaceStore } from '@wordpress/interface';
+import { useSelect } from '@wordpress/data';
+import { InterfaceSkeleton, FullscreenMode, ComplementaryArea } from '@wordpress/interface';
 import { BlockBreadcrumb, BlockCanvas, store as blockEditorStore } from '@wordpress/block-editor';
 
 import Sidebar from './Sidebar';
+import { scope } from './constants';
 
 export default function BlockEditor() {
 		const { styles } = useSelect(( select ) => {
@@ -13,18 +13,13 @@ export default function BlockEditor() {
 				};
 		}, []);
 
-		const { enableComplementaryArea } = useDispatch( interfaceStore );
-		useEffect(() => {
-				enableComplementaryArea( 'tipus/editor', 'edit-post/block' );
-		}, []);
-
 		return (
 				<>
 						<FullscreenMode isActive={ true } />
 						<Sidebar />
 						<InterfaceSkeleton
 								content={ <BlockCanvas height="100%" styles={styles} /> }
-								sidebar={ <ComplementaryArea.Slot scope="tipus/editor" /> }
+								sidebar={ <ComplementaryArea.Slot scope={ scope } /> }
 								footer={ <BlockBreadcrumb /> }
 						/>
 				</>

editor/Sidebar.jsx

@@ -1,13 +1,23 @@
-import { useSelect } from '@wordpress/data';
+import { useSelect, useDispatch } from '@wordpress/data';
+import { useEffect } from '@wordpress/element';
 import { ComplementaryArea, store as interfaceStore } from '@wordpress/interface';
 import { Panel } from '@wordpress/components';
 import { BlockInspector } from '@wordpress/block-editor';
 
+import { scope } from './constants';
+const SIDEBARS_BLOCK = 'tipus/block';
+
 export default function Sidebar () {
+		const { enableComplementaryArea } = useDispatch( interfaceStore );
+		useEffect(() => {
+				enableComplementaryArea( scope, SIDEBARS_BLOCK );
+		}, []);
+
 		return (
 				<ComplementaryArea
-						scope="tipus/editor"
-						identifier="edit-post/block"
+						scope={ scope }
+						identifier={ SIDEBARS_BLOCK }
+						isActiveByDefault={ true }
 				>
 						<Panel>
 								<BlockInspector />

editor/constants.js

@@ -0,0 +1 @@
+export const scope = 'tipus/editor';