Experiments don't propagate correctly in notebooks when editing cells

[christopherswenson]

There seem to be some issues with propagation of model annotations between notebook cells; here's one case that I've been able to reproduce:

Steps to reproduce:

1. Create a new Malloy notebook.
2. Add a cell with ##! experimental.parameters
3. Add another cell and use parameters somehow: source: foo(param::string) is some_connection.table('some_table')
4. Edit the first cell: remove the "s" from "parameters" then add it back

Expected behavior:

• Removing the "s" from "parameters" should cause the parameter usage in the second cell to get a red underline
• Adding the "s" back should cause the error to go away

Actual behavior:

• Adding the "s" back does not cause the error to go away

Note: editing the second cell (e.g. just adding a space or editing a comment) causes the error to go away