Enhance Custom Toolbar Usability and Aesthetics of The Components Prop

[totitoti7]

Addresses issue #2574

This pull request introduces several enhancements to the custom toolbar, aiming to improve both usability and visual appeal:

• Clear "Today" Button: Replaced the ambiguous "." symbol with the explicit label "Today" for better clarity and user understanding.
• Consistent Styling: Matched the styling of the "Today" button to the other navigation buttons, creating a cohesive and visually consistent interface.
• Circular Hover Effect: Added a subtle circular shadow around the "<" and ">" buttons on hover, providing a clear visual cue for interaction and enhancing user experience.
• Clean Button Design: Removed default button borders and hover effects, resulting in a cleaner and more modern aesthetic.

These changes collectively contribute to a more user-friendly and visually appealing calendar interface.

Visual Demonstration:

• Attached is a screenshot showcasing the current toolbar.

• Video Recording: A short video demonstrating the improved user experience with the new toolbar design and the circular hover effect on navigation buttons

Screen.Recording.2024-04-26.at.6.00.12.PM.mov

I believe these enhancements will significantly improve the overall user experience of the React-Big-Calendar. I welcome feedback and discussion on these changes.