test(wasm): Cover Android soft keyboard input sequences

Replays the browser's composition and key event sequences on the hidden input:
Chrome and Safari commit orderings, a composition re-opened on existing text,
a preedit repeating adjacent text or emptied again, the caret moved and the
text cleared while a composition is open (including the browser's late
selectionchange for the replaced value), a preedit rejected by
BeforeTextChanging or coerced shorter than its start, a compositionend from
an input that focus() replaced, a read-only TextBox, a multiline TextBox
following the textarea's caret, and Backspace without a code in a TextBox and
a PasswordBox.

Author: mikernet