Add persistence storage

[lah7]

It's #888 plus some finishing touches. All tasks have been completed and it's working well - ready for a final review.

There are no open issues to close on this repository - the mentioned open issues are for front-ends.

Worth mentioning in the release notes:

• Lighting settings are retained across reboots.
  • This will cause your devices to reset to spectrum initially.
  • Applications will require an update to support this feature.
• Some devices (such as Chroma HDK and Base Station Chroma) no longer report 0% brightness.

[chabad360]

A known issue is that this doesn't monitor DPI changes via hardware buttons, so this won't be persisted until the state is updated via the API.

...or until #1124 is merged (which would allow for handling the buttons in userspace))

Well, it depends on how the buttons report, I only monitor hardware events that trigger evdev (i.e. keypress events), so it's not that simple...

[tildearrow]

I wonder what happened to this branch?...

It's been a while since it was last updated.

[z3ntu]

Error with e.g. Kraken Ultimate: (see #1266, polychromatic/polychromatic#287)

import openrazer.client as rclient
device = rclient.DeviceManager().devices[0]  # First device
device.fx.breath_single(255,255,255)
device.fx.breath_dual(255,255,255, 128,128,128)
device.fx.breath_triple(255,255,255, 128,128,128, 255,255,255)
device.fx.breath_dual(255,255,255, 128,128,128)  # Error happens

Traceback (most recent call last):
  File "a.py", line 6, in <module>
    device.fx.breath_dual(255,255,255, 128,128,128)  # Error happens
  File "/usr/lib/python3.8/site-packages/openrazer/client/fx.py", line 277, in breath_dual
    self._lighting_dbus.setBreathDual(red, green, blue, red2, green2, blue2)
  File "/usr/lib/python3.8/site-packages/dbus/proxies.py", line 141, in __call__
    return self._connection.call_blocking(self._named_service,
  File "/usr/lib/python3.8/site-packages/dbus/connection.py", line 652, in call_blocking
    reply_message = self.send_message_with_reply_and_block(
dbus.exceptions.DBusException: org.freedesktop.DBus.Python.TypeError: Traceback (most recent call last):
  File "/usr/lib/python3.8/site-packages/dbus/service.py", line 711, in _message_cb
    retval = candidate_method(self, *args, **keywords)
  File "/home/luca/dev/razer/openrazer/daemon/openrazer_daemon/dbus_services/dbus_methods/chroma_keyboard.py", line 479, in set_breath_dual_effect
    self.zone["backlight"]["colors"][0:6] = int(red1), int(green1), int(blue1), int(red2), int(green2), int(blue2)
TypeError: 'tuple' object does not support item assignment

[kevchu3]

I pulled this commit and tested, and was successfully able to resolve #1266

[kevchu3]

Would we be able to get this PR merged into master?