CigarStats.apply could give better error if internal clipping operators found

[mjhipp]

After #761, this apply method will fail during this loop if a clipping operator is found within the read, as it halts prematurely here:

fgbio/src/main/scala/com/fulcrumgenomics/alignment/Alignment.scala

Lines 124 to 131 in 57a72b4

	// aligned bases
	while (index < cigar.elems.length && !cigar.elems(index).operator.isClipping) {
	val elem = cigar.elems(index)
	lengthOnQuery += elem.lengthOnQuery
	lengthOnTarget += elem.lengthOnTarget
	if (elem.operator.isAlignment) alignedBases += elem.length
	index += 1
	}

The error just says that the cigar did not consume all elements:

java.lang.IllegalArgumentException: requirement failed: Invalid cigar, did not consume all the elements: 5M5I5D5N5S5H[5P5=5X]

It would be helpful if the error specified that there were clipping operators found in the middle of the read.