Support other gymnasium spaces in Direct workflow

[Toni-SM]

Description

This PR add supports for different Gymnasium spaces (Box, Discrete, MultiDiscrete, Tuple and Dict) to define observation, action and state spaces in the direct workflow.

See #864 (comment)

Type of change

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

Checklist

• I have run the pre-commit checks with ./isaaclab.sh --format
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• I have updated the changelog and the corresponding version in the extension's config/extension.toml file
• I have added my name to the CONTRIBUTORS.md or my name already exists there

[glvov-bdai]

Hi! Is it possible to add support for heterogeneous observation spaces for Manger Based Environments too? If this is already in the works is there any timeline on that front?