feat: add paper_size in SceneInfo

[Seb-sti1]

As discussed in #39, #34 (comment) and #34 (comment) there is a new property in SceneInfo called paperSize according to the debug output of remarkable software

I changed the test_blocks_keep_unknown_data_in_main_block as suggested by the comment. As it is in hex and a bit hard to read, here is an explanation of the modification made :

hex	signification	modifications
2E000000 0000010D	block definition	21 to 2E as the size of the SceneInfo is now 46 and not 33
1C 06000000 1F 0000 2F 0000	current_layer property	None
2C 05000000 1F 0000 21 01	background_visible property	None
3C 05000000 1F 0000 21 01	root_document_visible property	None
5C 08000000 7C050000 50070000	(new) paper_size property	Added as suggested by the comment
E1 FF	new, unknown data	None

I used the excess bytes 92, 8, 0, 0, 0, 124, 5, 0, 0, 80, 7, 0, 0 of #34 (comment)

Closes #39