Inaccurate type for TextInput's onChange property

[jclem]

Describe the bug

I expected the onChange property of TextInput to have the same type as JSX.InstrinsicElements['input'], but it appears that currentTarget on the event is more than HTMLInputElement:

To Reproduce
Steps to reproduce the behavior:

1. Create a component with TextInput whose value is a piece of string state
2. Try to set the string state with onChange={e => setState(e.currentTarget.value)}

Expected behavior

No type error occurs.

Screenshots

See above with the current typing for onChange.

[colebemis]

Added this to our planning project board. Thank you!