Add Bandits / MetaLM / MetaMaze (Survival)

[WorldEditors]

Add 2 New Environments

• Bandits
• MetaLM

Update MetaMaze

• Add task type of Survival
• Add discrete 3D Environments

[CLAassistant]

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1 out of 2 committers have signed the CLA.

:white_check_mark: WorldEditors
:x: wangfan04

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