CG-9706: Support imp.is_dynamic

[tawsifkamal]

Motivation

• Checks if the import is dynamic by checking if it's in the body of a function, method, if statement, etc
• Supports TSImport and PyImport

[linear]

CG-9706 Support `import.is_dynamic`

• Would be great to be able to say an import is top-level or not
• Same for JS - not have to mess with the edge cases here

See implementation here: https://www.codegen.sh/codemod/4897/code/22013/playground/diff

Make sure to update the docs! ("Imports and Exports")

This should enable us to detect this import in python:

if TYPE_CHECKING:
  from codegen import Codebase

def my_function():
  from codegen import MyFunction

Bonus: support JS! (what does this look like?)