Handling <textRegion> without nested <Coords>

[HugoSchtr]

If no layout annotation exists, only one <textRegion> element is created by eScriptorium in the PAGE XML export, with an attribute `id="eSc_dummyblock_". Baselines are then nested into that element.

However, when this occurs, no <Coords> element is nested inside the <textRegion>. The current XSLT is fetching text regions coordinates values with said element, resulting with an invalid TEI file.

This exception must be handled in the XSLT.

[HugoSchtr]

XSLT modified on branch handling_no_coords.