bindings: python: add a test case for line_event's __repr__
bindings: python: add a test case for line_event's __repr__

Check if an event's representation string is generated correctly.

Signed-off-by: Bartosz Golaszewski <108de5fbc428215dc26df4468b48691526611148@gmail.com>

brgl/libgpiod,brgl/libgpiod,brgl/libgpiod,brgl/libgpiod