Add bin picking environment

[palanc]

1. Fixes small bugs when offscreen rendering (e.g w/ examine_env.py)
2. Adds an environment for picking a block from a shallow bin (requires Add a bin with low height and sloped sides furniture_sim#2 be merged first)
3. Allows examine_env.py to load a policy hard-coded into a class. Try testing with
   MJPL python robohive/utils/examine_env.py -e FrankaBinPick-v0 -p robohive.envs.arms.bin_pick_v0.BinPickPolicy

[vikashplus]

@palanc -- can we get this rebased on main and PR send to dev branch.

[vikashplus]

@palanc -- can we break this down into smaller PRs. It will help with merges.

[vikashplus]

@palanc -- will it be possible to break the PR down into individual updates? It will help the preparing and merging easier