Add code injection dropdown

[Nathan-Nesbitt]

We need to simplify the coding process by allowing students to just select "template" code which does some functionality where the cursor has been placed. This shouldn't be super complicated as we will just have to generate some common tasks like:

1. Create Connection
2. Create a command
3. Create a datastore
4. Create a callback function
5. Store a value
6. Create an event handler
7. Create a Model (MinecraftLearns)
8. Process the model data
9. Train the model
10. Save the model
11. Predict using the model
12. Load a model
13. Create a plot

We should also have it broken down into each of the libraries (Game, DataStore, and MinecraftLearns)