fix: added of modal lock countdown

[GuiLeme]

What does this PR do?

This PR implements an optional delay before the picked user modal can be closed, preventing accidental dismissals from misclicks. The changes include:

• Configuration System: Added preventCloseDelaySeconds setting (default: 3 seconds) to control modal close delay
• Countdown Logic: Implemented timer that prevents closing via close button, overlay click, or Escape key during countdown
• Visual Indicators:
  • For Viewers: Text message displaying "You can close this modal in X seconds"
  • For Presenters: Smooth blue progress bar at the bottom of the modal that shrinks over time

Closes Issue(s)

Closes #59

Motivation

When a user is randomly picked, the modal appears to notify participants. However, users can accidentally close this important notification with a misclick before seeing who was selected. This feature adds a configurable delay to ensure users have time to acknowledge the selection, improving the overall user experience and reducing confusion in meetings.

More

• Added/updated documentation (README.md)
• Added internationalization support (en.json)

Configuration Example:

public:
  plugins:
    - name: PickRandomUserPlugin
      settings:
        preventCloseDelaySeconds: 3  # Set to 0 to disable

See demo (I set the delay to be of 10 seconds via configuration, but the default is 3):

demo_pick-random-user.mp4