[BUG]: Inconsistencies in sidebar

[Spiral-Memory]

Description:

The sidebar exhibits multiple design inconsistencies, including the following:

1. Unable to render "invite members".
2. Irregular padding in the messagebox.
3. No date rendering on the first message in Pinned and Starred Messages.
4. Text overflows in sidebar when code formatting is present in messages.
5. Sidebar becomes scrollable when overflowing, which is not user-friendly.
6. Room avatar is not centered.
7. Refactoring is required for Pinned, Starred, and Files according to Sidebar component.
8. UI unable to render due to no validation of messageList size
9. Throbber needed in UserMentions and Files
10. [Additional] : Ellipsis required in dynamic header

Steps to reproduce:

1. Set up Embedded Chat.
2. Experiment with the sidebar and observe the unexpected behavior mentioned above.

Actual behavior:

https://github.com/RocketChat/EmbeddedChat/assets/78961432/3da1949f-04a4-4703-ae1f-e87b2e3b4f4e