move_object anchored the object to the paragraph under the drop point and
computed the offset from that paragraph origin. With a Square-wrapped object
the surrounding text reflows once the object moves away, so the first
paragraph of the target page - the anchor when dropping near its top -
slides back to the previous page and the object follows it.
Re-check the page after placing an object across pages and re-anchor when the
placement did not land on the target page (up to three attempts). Same-page
moves still place once, so resize and nudge are unchanged.
Adds a kittest that presses, moves and releases onto the top of the next page
and asserts the object stays on the page under the pointer.
Co-authored-by: Brandon Thomas <echelon@gmail.com>
GavinQiErandBrandon Thomas
8bde3b3c25