add overlap & segment_size flag for python cli task create

[foreverYoungGitHub]

Motivation and context

Allow users to create the cvat task with multiple jobs through cvat python cli.

How has this been tested?

Since cli tools does not have the automatic test, I directly test it with my own task.

The task create with default param:

The task create with --overlap=0 --segment_size=31:

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

[bsekachev]

@foreverYoungGitHub

Hi, thx for the contribution
Could you please resolve conflicts?

[azhavoro]

@foreverYoungGitHub Thanks again for the PR, could you please fix tests and update changelog?

ERROR: test_tasks_dump (tests._test_cli.TestCLI)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python3.5/unittest/mock.py", line 1157, in patched
    return func(*args, **keywargs)
  File "/home/django/utils/cli/tests/_test_cli.py", line 32, in setUp
    [self.img_file])
TypeError: tasks_create() missing 2 required positional arguments: 'resource_type' and 'resources'

[foreverYoungGitHub]

@azhavoro, Sorry for the error message in the test, should be fine for now.

[coveralls]

Pull Request Test Coverage Report for Build 6658

• 3 of 3 (100.0%) changed or added relevant lines in 2 files are covered.
• 7 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.03%) to 64.987%

---

Files with Coverage Reduction	New Missed Lines	%
cvat/apps/engine/task.py	1	76.95%
cvat/apps/engine/media_extractors.py	6	75.81%

Totals
Change from base Build 6627:	-0.03%
Covered Lines:	11099
Relevant Lines:	16677

---

💛 - Coveralls

[bsekachev]

@foreverYoungGitHub Thanks you so much