Rewrite: APNs: Scoped App Tokens

[JJTech0130]

Allows receiving notifications sent from the public APNs API

• ACK incoming notifications
• Set sleep power state/active interval
• Automatically filter topics
• Keep track of scoped tokens internally
• Rework await connected API
• Embed personal key for sending test notifications in tests
• Add CLI tool

[JJTech0130]

Note to self: the current receive API relies on the fact that the network is slower to respond than the scheduler is to schedule the receive task, as there is no backlog.
Not necessarily an incorrect assumption, but should be noted.

[JJTech0130]

The API is finished, it involved developing a new "Stream Filters" mechanism internally, but it leads to a nice clean test like this:

@pytest.mark.asyncio
async def test_scoped_token():
    async with apns.create_apns_connection(
        *await apns.activate(), courier="1-courier.sandbox.push.apple.com"
    ) as connection:

        token = await connection.mint_scoped_token("dev.jjtech.pypush.tests")

        test_message = f"test-message-{uuid.uuid4().hex}"

        # Not part of pypush, uses Apple's public APNs API
        await send_test_notification(token.hex(), test_message.encode())

        await connection.expect_notification(
            "dev.jjtech.pypush.tests",
            token,
            lambda c: c if c.payload == test_message.encode() else None,
        )

[JJTech0130]

New notifications subcommand, for example:
pypush notifications dev.jjtech.pypush.tests --sandbox

Note that it currently does not provide any method of saving the certificate or tokens used.

You can test it out using your own CloudKit console if you have a Developer ID, or use the .pem file in the tests/assets/ directory and use it with any of the online APNs test websites.