Refactoring the npm installation process for JavaScript

[rudolf101]

Description

The process of checking and installing npm packages has received a number of enhancements:

• Optimized the process of checking npm packages, now it takes about 2 seconds to check all packages, instead of 5-6 earlier
• Added a notification to the user about problems with the Internet connection when the timeout expires during the installation of npm packages ("Requirement installation error" title changed to "Failed to install requirements"):

Fixes #1829
Fixes #1882

How to test

Manual tests

Various scenarios have been tested. You can find the examples in the folder `/utbot-js/samples' and try to run UTBot.

Self-check list

• I've set the proper labels for my PR (at least, for category and component).
• PR title and description are clear and intelligible.
• I've added enough comments to my code, particularly in hard-to-understand areas.
• The functionality I've repaired, changed or added is covered with automated tests.
• Manual tests have been provided optionally.
• The documentation for the functionality I've been working on is up-to-date.