Should UI controls accept `None` for text?

[cspotcode]

arcade/arcade/gui/widgets/dropdown.py

Lines 64 to 66 in 2381082

	self._default_button = UIFlatButton(
	text=self._value, width=self.width, height=self.height
	)

self._value might be None, but UIFlatButton claims it won't accept None.

self._default_button = UIFlatButton(
    text=self._value, width=self.width, height=self.height
)

[gran4]

Look at line 42:
instead of default: Optional[str] = None
how about
default: str = ""

[eruvanos]

With None the developer has the option to say, nothing is selected, while an empty string could be a valid option.
While checking the code I fixed some bug (#1806)

Feel free to reopen this issue, if you still have concerns.