updated bbox jsons and added code to load bbox

src/ptbench/data/loader.py

src/ptbench/data/tbx11k_simplified/__init__.py

src/ptbench/data/tbx11k_simplified/default.json.bz2

src/ptbench/data/tbx11k_simplified/fold_0.json.bz2

src/ptbench/data/tbx11k_simplified/fold_1.json.bz2

src/ptbench/data/tbx11k_simplified/fold_2.json.bz2

src/ptbench/data/tbx11k_simplified/fold_3.json.bz2

src/ptbench/data/tbx11k_simplified/fold_4.json.bz2

src/ptbench/data/tbx11k_simplified/fold_5.json.bz2

src/ptbench/data/tbx11k_simplified/fold_6.json.bz2

src/ptbench/data/tbx11k_simplified/fold_7.json.bz2

src/ptbench/data/tbx11k_simplified/fold_8.json.bz2

src/ptbench/data/tbx11k_simplified/fold_9.json.bz2

src/ptbench/data/tbx11k_simplified_RS/__init__.py

src/ptbench/data/tbx11k_simplified_RS_v2/__init__.py

src/ptbench/data/tbx11k_simplified_RS_v3/__init__.py

src/ptbench/data/tbx11k_simplified_v2/__init__.py

src/ptbench/data/tbx11k_simplified_v2/default.json.bz2

src/ptbench/data/tbx11k_simplified_v2/fold_0.json.bz2

src/ptbench/data/tbx11k_simplified_v2/fold_1.json.bz2