Function handle_path 

pub async fn handle_path(
    req: HttpRequest,
    body: String,
    state: Data<AppState>,
) -> Result<HttpResponse, HaystackError>

Finds the shortest path between two entities.

Request Grid Columns

Column	Kind	Description
from	Ref	Source entity
to	Ref	Destination entity

Response Grid Columns

All entity tags plus pathIndex (Number, 0-based position in path).