Previously, when a w:p paragraph contained runs with textboxes,
the entire paragraph was replaced by just the textbox content,
discarding all other runs (including image-bearing runs).
Now we walk the paragraph's children in order, grouping
non-textbox content into copies of the original w:p and splicing
unwrapped textbox content in place, preserving the original order.
We also treat text inside a textbox containing an image as a
figure caption. (One often finds captioned images of this
kind in docx files.)
Closes#11510.
Closes#6893.
Closes#11412.
Closes#5394.
Closes#9633.
Co-Authored-By: Claude <noreply@anthropic.com>
