Add VK Cloud TTS and STT support

[putnik]

Description

VK Group (ex-Mail.ru group) is a big Russian company that has their own personal assistant Marusia. They allow to use same technologies in their cloud services.

VK Cloud supports two authorisation methods: one time tokens and service tokens without expiration. For now there is only service tokens support.

I don't really like the response time of the TTS service, but STT works very well. For now they support only Russian language.

How to test

1. Register a new VK Cloud account: https://mcs.mail.ru/
2. Confirm your email and phone number.
3. You will get 100 free roubles.
4. Create service token for Cloud Voice.
5. Edit mycroft.conf:

   "tts": {
   "module": "vk",
   "vk": {
   "service_token": "YOUR_SERVICE_TOKEN",
   "tempo": 1.15
   }
   },
   "stt": {
   "module": "vk",
   "vk": {
   "credential": {
     "service_token": "YOUR_SERVICE_TOKEN"
   }
   }
   }

   tempo is optional. Possible values: 0.75-1.75.

[pep8speaks]

Hello @putnik! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers:

Comment last updated at 2021-11-05 08:45:54 UTC

[devops-mycroft]

Voight Kampff Integration Test Succeeded (Results)

[krisgesling]

Hey Putnik - this looks great - thanks!

We've recently added a plugin system so that services like this can exist independently of Mycroft-core as an independent Python pacakge. In terms of the code, the shift is pretty minimal.

We've got some documentation about the new system here: https://mycroft-ai.gitbook.io/docs/mycroft-technologies/mycroft-core/plugins

and if you have any trouble getting it to work please shout out.

In the meantime I'm going to close this PR, but feel free to ask questions here or in Chat.

[putnik]

Thanks for the advice. I've published it as a plugin: https://pypi.org/project/mycroft-plugin-vk-cloud/