Marker placement does not occur in verse ranges

Verse ranges are represented as multiple rows in a UsfmUpdateBlock, only the first of which is non-empty. The marker placement algorithm uses only one alignment matrix, defaulting to the last, which is empty in the case of a verse range. This results in markers not being placed for verse ranges.

Here is a failing test for this case:

source = "This is the first part. This is the second part."
    pretranslation = "Esta es la primera parte. Esta es la segunda parte."
    align_info = PlaceMarkersAlignmentInfo(
        source_tokens=[t for t in TOKENIZER.tokenize(source)],
        translation_tokens=[t for t in TOKENIZER.tokenize(pretranslation)],
        alignment=to_word_alignment_matrix("0-0 1-1 2-2 3-3 4-4 5-5 6-6 7-7 8-8 9-9 10-10 11-11"),
        paragraph_behavior=UpdateUsfmMarkerBehavior.PRESERVE,
        style_behavior=UpdateUsfmMarkerBehavior.STRIP,
    )
    empty_align_info = PlaceMarkersAlignmentInfo(
        source_tokens=[],
        translation_tokens=[],
        alignment=to_word_alignment_matrix(""),
        paragraph_behavior=UpdateUsfmMarkerBehavior.PRESERVE,
        style_behavior=UpdateUsfmMarkerBehavior.STRIP,
    )
    usfm = r"""\id MAT
\c 1
\v 1-2 This is the first part.
\p This is the second part.
"""
    result = r"""\id MAT
\c 1
\v 1-2 Esta es la primera parte.
\p Esta es la segunda parte.
"""

    rows = [
        UpdateUsfmRow(scr_ref("MAT 1:1"), str(pretranslation), metadata={"alignment_info": align_info}),
        UpdateUsfmRow(scr_ref("MAT 1:2"), "", metadata={"alignment_info": empty_align_info}),
    ]
    target = update_usfm(rows, usfm, update_block_handlers=[PlaceMarkersUsfmUpdateBlockHandler()])
    assert_usfm_equals(target, result)