Implement Undo functionality

[Abdulbaqi-Alshareef]

📒 Description

🕶️ Types of changes

New feature** (non-breaking change which adds functionality)

🤯 List of changes

-Support Undo deletion.
-Avoid interrupting the running time entry so you can undo the deletion while having time entry running.

👫 Relationships

Closes #4077

🔎 Review hints

-Delete one or more time entries.
-Right-click on TimeEntry List (same as you do when removing time entry) and choose "Undo delete time entry"
-This PR only supports Undo not Redo(I can add it if requested).
-Undo only supports the deletion of time entries.
-You can use undo only using the mouse, ctrl + z reserved for another functionality.

[skel35]

Thanks for the contribution @Abdulbaqi-Alshareef!

I have not fully reviewed and tested the PR yet, but I have 2 notes based on my initial review:

1. Ctrl+Z can be supported if the keyboard focus is inside the time entry list. It should be straightforward to add.
2. Why do we need a TimeEntrySnapshot class? TogglTimeEntryView should fit here.

[Abdulbaqi-Alshareef]

-You are right, at first, I wrote TimeEntrySnapshot class at first steps implementing the function but now no need for it.
-I added Ctrl+Z shortcut to undo deletion, and it only works if the time entry list got focused and that's difficult for the user due to the timer's behavior to retain focus.