feat: Add three animations that together simulate a typing animation

[VinhPhmCng]

AddTextLetterByLetterWithCursor

https://github.com/ManimCommunity/manim/assets/111203113/ac521507-03ba-483e-89a9-4edfbc928f0f

RemoveTextLetterByLetterWithCursor

https://github.com/ManimCommunity/manim/assets/111203113/f68e58a3-7230-44cd-bc53-b5b7b3136afa

Blink

https://github.com/ManimCommunity/manim/assets/111203113/df89b695-de47-4dbd-870f-dcad0fe409e2

Simple sequence

https://github.com/ManimCommunity/manim/assets/111203113/1a8bd04b-a5c1-4373-b497-c257ce7e142d

Motivation and Explanation: Why and how do your changes improve the library?

Simple animations that help create typing effects.

Further Information and Comments

I reverted by accident.

Reviewer Checklist

• [ ] The PR title is descriptive enough for the changelog, and the PR is labeled correctly
• [ ] If applicable: newly added non-private functions and classes have a docstring including a short summary and a PARAMETERS section
• [ ] If applicable: newly added functions and classes are tested

[VinhPhmCng]

Thanks for the reviews @JasonGrace2282 !

[MrDiver]

🤔 I would challenge the naming scheme a bit. Especially to make it a ~tiny bit shorter.

TypeTextWithCursor UntypeTextWithCursor

Or maybe also remove Text from the name.

Any complaints ? (Except that it does not match the previously existing functions)

[VinhPhmCng]

Any complaints ? (Except that it does not match the previously existing functions)

None. SGTM! Yeah I think we can remove Text even, since the user can infer that from Type and Untype. But I'm OK either way.

BTW, sorry if this is a silly question. But who will make the change?