Modify the plants service and related code in NodeJS to remove the plants service's collection of plants

[curieos]

Currently, the plants service holds a "cached" collection of the plants. This causes issues with #14 if the edit page is navigated to for a specific plant before the list page, since the current implementation relies on this cached information. The code will need to be modified to remove this collection on the Angular side, and to pass additional information about the plant on the NodeJS side.