Add auto inference of host scheme in CLI

[zhiltsov-max]

Motivation and context

Resolves openvinotoolkit/datumaro#30

• Added auto inference of host url schema in CLI, if it is provided in the url

How has this been tested?

Manual test

Checklist

• I submit my changes into the develop branch
• I have added description of my changes into CHANGELOG file
• I have updated the documentation accordingly
• I have added tests to cover my changes
• I have linked related issues (read github docs)
• I have increased versions of npm packages if it is necessary (cvat-canvas,
  cvat-core, cvat-data and cvat-ui)

License

• I submit my code changes under the same MIT License that covers the project.
  Feel free to contact the maintainers if that's a concern.
• I have updated the license header for each file (see an example below)

# Copyright (C) 2020 Intel Corporation
#
# SPDX-License-Identifier: MIT

[coveralls]

Coverage decreased (-0.01%) to 64.8% when pulling 990f61d on zm/cli-infer-host-schema into 5052737 on develop.

[ilouzl]

You may drop the 'https' argument from function declaration, aren't you?

[zhiltsov-max]

There is a parameter in CLI to enforce https, which uses this function parameter.