Configurable device info

[DarkCat09]

There's a probability that our static useragent will be banned (though afaik MAX hasn't blocked anyone by UA yet)

vkmax/vkmax/client.py

Lines 175 to 185 in 4e7d820

	"userAgent": {
	"deviceType": "WEB",
	"locale": "ru_RU",
	"osVersion": "macOS",
	"deviceName": "vkmax Python",
	"headerUserAgent": USER_AGENT,
	"deviceLocale": "ru-RU",
	"appVersion": APP_VERSION,
	"screen": "956x1470 2.0x",
	"timezone": "Asia/Vladivostok"
	},

It may be suspicious when a user sign-ins with Asia/Vladivostok timezone if previously they never was in that timezone. Same for osVersion key. And deviceName has kinda the most careless default value.

Letting a developer set any device info is not an option too. Also take into account that MAX silently ignores invalid handshake packets.

I think we should create several enums with possible values for user-agent parts

[DarkCat09]

If #27 gets implemented, it'd make sense to make several different userAgent-s that are chosen either randomly or by developer on a first login, and that bundled userAgent-s should be some popular devices like xiaomi or whatever, so we won't be blocked immediately