The source icon button from createSourceWrapper, without the content wrapper around it, so
it can be placed anywhere. Pair it with createExpandingSource using the same
rawKeyChain, rendered in the same shadow root. Clicking it dispatches a
SourceExpansionEvent that the caller must store into options.currentlyExpanded. Renders
nothing when there are no sources. Style it with sourceWrapperStyles.
The source icon button from createSourceWrapper, without the content wrapper around it, so it can be placed anywhere. Pair it with createExpandingSource using the same
rawKeyChain, rendered in the same shadow root. Clicking it dispatches a SourceExpansionEvent that the caller must store intooptions.currentlyExpanded. Renders nothing when there are no sources. Style it withsourceWrapperStyles.