allow getting the DocumentOffset for any node+offset, not just focusNode
allow getting the DocumentOffset for any node+offset, not just focusNode

we need this to get both offsets of the selection boundaries

getSelectionOffsetAndText offers the extra flexibility,
getCaretOffsetAndText keeps the old api for focusNode/focusOffset

Also did some renaming here now that it's not just for the caret anymore

matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk