fix(textinput): set cursor on initial value

This reverts the code back to the logic from 4ce16e8 which fixed the
issue of the cursor not being moved when an initial value was set with
SetValue.

The fix regressed in 16053f4.

textinput/textinput.go

@@ -205,7 +205,7 @@ func (m *Model) SetValue(s string) {
 	} else {
 		m.value = runes
 	}
-	if (m.pos == 0 && len(m.value) == 0) || m.pos > len(m.value) {
+	if m.pos == 0 || m.pos > len(m.value) {
 		m.setCursor(len(m.value))
 	}
 	m.handleOverflow()