feat(flow-item): expose FlowItemLike type (#11791)

**Related Issue:** #11750 

## Summary

Expose the `FlowItemLike` type, which can be imported via:

```ts
import type { FlowItemLike } from "@esri/calcite-components/dist/components/calcite-flow/types"
```

Author: benelan

packages/calcite-components/src/components/flow/types/index.ts

@@ -0,0 +1 @@
+export type { FlowItemLike } from "../interfaces";