Fix intelligent scissors blocking

[klakhov]

Motivation and context

Intelligent scissors blocking feature is not working on Windows
It seems that keydown event is fired again and again when Ctrl key is held
Resolved #3582

How has this been tested?

Manual testing

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) 2021 Intel Corporation
#
# SPDX-License-Identifier: MIT

[bsekachev]

Please, fix these linter issues.
@dvkruchinin Could you please look at canvas3d_functionality_2 tests. They are failed again.