fix!: reboot_host instead of reboot; drop run_device_action (0.2.0)

The gateway had reboot(), but the contract (HostRebootMixin) and the
application look for reboot_host(), so the gateway could not be
restarted from it. reboot_host() returns None and raises when the
gateway refuses, as the contract says.

run_device_action dispatched reboot, restart_wifi[:band] and
get_diagnostics by string, with a result shape other than its
contract's. restart_wifi(band) and get_diagnostics() are methods now;
napalm-device-types deprecates run_device_action.

BREAKING CHANGE: reboot() and run_device_action are removed.

Closes #5. Part of #6.

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "napalm-zyxel"
-version = "0.1.0"
+version = "0.2.0"
 description = "NAPALM driver for Zyxel VMG series residential gateways (VMG4005-B50A and similar)."
 readme = "README.md"
 license = { text = "Apache-2.0" }