Add Huawei LTE router platform, device tracker, and sensor

[scop]

Description:

Add Huawei LTE router platform, device tracker, and sensor.

Pull request in home-assistant.github.io with documentation (if applicable): home-assistant/home-assistant.io#6229

Example entry for configuration.yaml (if applicable):

huawei_lte:
  url: 'http://192.168.100.1/'
  username: 'admin'
  password: 'meh'

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in home-assistant.github.io

If the code communicates with devices, web services, or third-party tools:

• New dependencies have been added to the REQUIREMENTS variable (example).
• New dependencies are only imported inside functions that use them (example).
• New or updated dependencies have been added to requirements_all.txt by running script/gen_requirements_all.py.
• New files were added to .coveragerc.

If the code does not interact with devices:

• Tests have been added to verify that the new code works.

[mu3]

@scop @abmantis

Not sure where to submit a feature request for this specific platform, so I’ll try here:

Ability to access SMS on the router.
Ultimately, to use as a trigger in HASS automations.

[MartinHjelmare]

You should only file an issue if you found a bug. Feature and enhancement requests should go in the Feature Requests section of our community forum. Thanks!