Optional chaining plugin for cvat-ui and cvat-canvas

[ActiveChooN]

Motivation and context

PR added @babel/plugin-proposal-optional-chaining plugin for cvat-ui and cvat-core to support optional chaining feature (propossal)

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]

Coverage remained the same at 64.814% when pulling 1ae57ba on dk/babel-optional-chaining into 4841f83 on develop.