Inconsistent data models for bbox

[HiromuHota]

Describe the bug

Data models that represent bounding boxes are inconsistent, which considerably degrades readability.
For example,

bbox: List[float] in the order of (y0, x0, y1, x1) at

pdftotree/pdftotree/TreeExtract.py

Line 447 in 6ff4a7c

f"bbox {int(box[1])} {int(box[0])} {int(box[3])} {int(box[2])}",

bbox: Tuple[float] in the order of (x0, y0, x1, y1) at

pdftotree/pdftotree/TreeExtract.py

Line 456 in 6ff4a7c

" ".join(["bbox"] + [str(int(_)) for _ in elem.bbox]),

word[1:]: List[float] in the order of (y0, x0, y1, x1) at

pdftotree/pdftotree/TreeExtract.py

Lines 458 to 463 in 6ff4a7c

	words = self.get_word_boundaries(elem)
	for word in words:
	top = int(word[1])
	left = int(word[2])
	bottom = int(word[3])
	right = int(word[4])

To Reproduce

N/A

Expected behavior

I expect that they are consistent.

Error Logs/Screenshots

N/A

Environment (please complete the following information):

• pdftotree Version: 6ff4a7c

Additional context
Add any other context about the problem here.

See discussions at #84 (comment)