fix: broken plugin and tests after #115

[artus9033]

Describe your changes

While #115 introduced changes that fixed some bugs, at the same time it carried some logic changes to improve code quality and add more clear configuration priority handling that appeared to be faulty and thus cause E2E tests to fail. Since #115 was an external fork, CI status checks were not shown and it has been merged.

This PR adds:

• checkDraggingConfiguration and proper unit tests for this function to relieve the above problem
• reorganized jest configuration so that options that are only allowed in global configuration (e.g. coverage-related ones), are not located in project configuration
• adds test.step blocks to E2E tests to make logs more intuitive to read
• adds deep-copying to setupChartInstance test utility so that there is no chance changes to chart properties are persisted across tests
• enables verbose logging in jest tests to show test suites with their titles as they are run
• speeds up E2E tests a bit thanks to moving a beforeEach block in configurationChanges.spec.ts (it has been run multiple times for each test)

Linked issues (if any)

• Added custom interaction mode option #115

Checklist before requesting a review

• E2E tests' snapshots (screenshots) are up-to-date
• documentation is up-to-date