[CP-3020] Hidden new Help behind a flag

[mkurczewski]

JIRA Reference: CP-3020

:memo: Description ️

• Hidden new help behind a NEW_HELP_ENABLED=1 flag
• Fixed help update propagation when app window is unfocused

:muscle: Checklist before requesting a review - nice to have

• getState function in async thunk actions is correctly typed
• redux selectors are used in components / prop drilling is reduce

:exclamation: Checklist before merging a pull request

• change went through the QA process
• translations are updated in dedicated application
• CHANGELOG.md is updated