feat(editor): Migrate pinData mixin to usePinnedData composable (no-changelog) (#8207)

## Summary
Required as part of NodeView refactoring:
- Migrates `pinData` mixin to `usePinnedData` composable.
- Adds `useActiveNode` and `useNodeType` composables 

## Related tickets and issues
https://linear.app/n8n/issue/N8N-6355/pindata

## Review / Merge checklist
- [x] PR title and summary are descriptive. **Remember, the title
automatically goes into the changelog. Use `(no-changelog)` otherwise.**
([conventions](https://github.com/n8n-io/n8n/blob/master/.github/pull_request_title_conventions.md))
- [x] [Docs updated](https://github.com/n8n-io/n8n-docs) or follow-up
ticket created.
- [x] Tests included.
> A bug is not considered fixed, unless a test is added to prevent it
from happening again.
   > A feature is not complete without tests.

packages/editor-ui/src/composables/useNodeHelpers.ts

@@ -113,7 +113,7 @@ export function useNodeHelpers() {
 		workflow: Workflow,
 		ignoreIssues?: string[],
 	): INodeIssues | null {
-		const pinDataNodeNames = Object.keys(workflowsStore.getPinData ?? {});
+		const pinDataNodeNames = Object.keys(workflowsStore.pinnedWorkflowData ?? {});
 
 		let nodeIssues: INodeIssues | null = null;
 		ignoreIssues = ignoreIssues ?? [];