Issue #116: Add observation of angle between instrument and target

[LorenzzoQM]

Description

Closes #116

Now it is possible to add the angle between the sensing instrument and the target in the observations using the target_angle option.

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)

How should this pull request be reviewed?

• By commit
• All changes at once

How Has This Been Tested?

Please describe the tests that you ran to verify your changes.

Passes Tests

• Unit tests (General Environment only) pytest --cov bsk_rl/envs/general_satellite_tasking --cov-report term-missing tests/unittest
• Integrated tests (General Environment only) pytest --cov bsk_rl/envs/general_satellite_tasking --cov-report term-missing tests/integration
• Examples (General Environment only) pytest tests/examples

Test Configuration

• Python: 3.11.6
• Basilisk: 2.2.2
• Platform: MacOS Sonoma 14.2.1

Checklist:

• My code follows the style guidelines of this project (passes Black, ruff, and isort)
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• Commit messages are atomic, are in the form Issue #XXX: Message and have a useful message
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works

[Mark2000]

Could you add a unit test or two for this functionality? Otherwise looks good

[Mark2000]

Looks good to me!