feat(cursor): Add a method to retrieve the character underneath the cursor.

[kyleochata]

Added a method to get the character beneath the Cursor.

• func (m Model) GetChar() string

Ran into an edge case that can benefit from just knowing the character that is underneath the cursor.

[meowgorithm]

Interesting! What's the edge case?

[kyleochata]

After getting some sleep I realized I overlooked textinput.Position() while navigating through a textinput.

Could be useful as a quality of life change for a character check rather than calling Position() and Value()

[meowgorithm]

Would love to hear your actual use case so as to better ascertain if something like this makes sense.