Wraps unit tests with build_simulation_context method

[Mayankm96]

Description

This MR modifies the tests to use build_simulation_context instead of the repeated code for setUp and tearDown. It still needs to be propagated everywhere.

Fixes # (issue)

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 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

[Mayankm96]

I won't have time to work on this anymore. If @jsmith-bdai or someone else wants to bite the bullet and do it for all the tests, feel free to take over the branch.