Replace file system watcher with polling

[z4kn4fein]

Describe the purpose of your pull request

In this PR I replaced FileSystemWatcher with polling on file changes with 1s interval. For example, FileSystemWatcher didn't work on Linux in a docker container.

Also, removed the init state waiting nonsense and replaced it with a synchronous file read in the constructor.

Requirement checklist (only if applicable)

• [x] I have covered the applied changes with automated tests.
• [x] I have executed the full automated test set against my changes.
• [x] I have validated my changes against all supported platform versions.
• [x] I have read and accepted the contribution agreement.

[sonarcloud[bot]]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

93.2% Coverage
0.0% Duplication