Cypress. Fix case 108 for Firefox.

[dvkruchinin]

Motivation and context

Related #3961
I slightly reworked the test due to the fact that in Firefox the shape does not have the css transform property.
A solution of the form

const shapeAttrs = shape2.attr('transform').split('(')[1].split(')')[0].split(',');

it looks ugly.
Found a solution using getCTM().
CI for check: https://github.com/dvkruchinin/cvat/runs/4394611968?check_suite_focus=true

How has this been tested?

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