This adds back a function available in 3.x: exporting the GDScript
files in a binary form by converting the tokens recognized by the
tokenizer into a data format.
It is enabled by default on export but can be manually disabled. The
format helps with loading times since, the tokens are easily
reconstructed, and with hiding the source code, since recovering it
would require a specialized tool. Code comments are not stored in this
format.
The `--test` command can also include a `--use-binary-tokens` flag
which will run the GDScript tests with the binary format instead of the
regular source code by converting them in-memory before the test runs.
