CVAT XML file should have only one <original_size> tag -- breaks import of cvat project annotations

[ramelito]

As user i want to import dataset in cvat format which has not just one task but project which contains many tasks. As project contains many tasks therefore there more than one <original_size>.

[LiberiFatali]

Yes, support for this format should be aligned with the cvat format version (1.1 now)