Change V2.0 coors (#2380)

* Refactor (all): change coordinate system

* Fix (mask_head): fix cat -1 bug in mask_paste

* Fix (unittest)
: modify unittest and pass CI

* reformat to pass CI

* Fix round coordinates bugs

* clean file

* Fix (test): use cpu version of aligned roi_align in tests

* Refactor (mask): clean np.stack

* Refactor (head): reformat code and fix missing -1

* Reformat: reformat and add doc strings

* Refactor (mask_head): more clea docstring