Added ability to configure email verification for registered user

[azhavoro]

Resolve #1730,

THIS PR makes CVAT is ready to configure email verification for registered user with django-allauth app.

Motivation and context

It's important to have ability to verify user emails that can be used to restore password in future.

How has this been tested?

Manually

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]

Pull Request Test Coverage Report for Build 7081

• 16 of 18 (88.89%) changed or added relevant lines in 3 files are covered.
• 56 unchanged lines in 3 files lost coverage.
• Overall coverage increased (+0.01%) to 69.735%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
cvat/apps/authentication/auth_basic.py	4	5	80.0%
cvat/apps/authentication/urls.py	5	6	83.33%

Files with Coverage Reduction	New Missed Lines	%
src/user.js	11	52.17%
src/api-implementation.js	13	77.03%
src/api.js	32	55.13%

Totals
Change from base Build 7079:	0.01%
Covered Lines:	11762
Relevant Lines:	16408

---

💛 - Coveralls

[nmanovic]

@azhavoro , please resolve conflicts?

[nmanovic]

@zhiltsov-max , could you please look and test the PR?

[zhiltsov-max]

A bit of documentation on this feature wouldn't be extraneous. I have a suspicion, that enabling mandatory verification after a user has registered won't re-send an verification email.

[azhavoro]

These settings can be used to test this PR (base.py):

# https://github.com/pennersr/django-allauth
ACCOUNT_AUTHENTICATION_METHOD = 'username'
ACCOUNT_CONFIRM_EMAIL_ON_GET = True
ACCOUNT_EMAIL_REQUIRED = True
ACCOUNT_EMAIL_VERIFICATION = 'mandatory'
OLD_PASSWORD_FIELD_ENABLED = True

# Email backend settings for Django
EMAIL_BACKEND='django.core.mail.backends.console.EmailBackend'

Could you please add documentation about the feature into installation.md?

[nmanovic]

LGTM

[nmanovic]

Why did you revert these changes?

[nmanovic]

Andrey, you have reverted a couple of PRs. It is my change to fix swagger after commit of serverless.