Make the binary reader's SpanProvider facet work with Ion 1.1 e-expressions and delimited containers

[tgregg]

The binary SpanProvider implementation sets the current span's end index using the value marker: https://github.com/amazon-ion/ion-java/blob/master/src/main/java/com/amazon/ion/impl/IonReaderContinuableTopLevelBinary.java#L269

This works fine in Ion 1.0 because every value is length-prefixed, so the value marker's end index is always greater than or equal to its start index. However, the value markers for Ion 1.1's e-expressions and delimited containers will have end index = -1 until fully read. As currently implemented, this makes the value of OffsetSpan.getFinishOffset() garbage for these encodings. This should be fixed.