This Babel plugin is for marking Forge UI JSX components
with unique key (property) __auxId.
The purpose of the key is to be consistent between renders, even when the code around it is inconsistent like this:
{showButtonOne && <Button text="Hello" />}
<Button text="World" />Without this Babel plugin, the "World" button may be marked Button.0 or Button.1,
depending on the value of showButtonOne.