Issue #58: Expose state vector element names

[Mark2000]

Description

Closes #58

Allows the user to print out a list of state names from sat observations. Can only be produced after environment initialization, since the shape of each observation element is unknown until then. For example

Observation: [ 5.55643668e-04 -8.20527293e-04 -2.82089986e-03  1.30471109e-03
              -2.84886806e-05  9.99999148e-01  5.31311297e-01 -5.76592276e-01
              -7.38774349e-01  5.67862249e-01  7.45917635e-01 -1.73853876e-01
               9.84419538e-01  4.82351662e-01  7.87235656e-01  2.62243219e-01
              -5.58111562e-01  6.60252514e-01  7.85183742e-01  2.64519689e-01
              -5.59924839e-01  4.17639105e-01  7.78825097e-01  2.71977900e-01
              -5.65207475e-01  3.44327485e-01]
States: ['omega_BP_P_normd[0]', 'omega_BP_P_normd[1]', 'omega_BP_P_normd[2]', 
         'c_hat_P[0]', 'c_hat_P[1]', 'c_hat_P[2]', 'r_BN_P_normd[0]', 'r_BN_P_normd[1]', 
         'r_BN_P_normd[2]', 'v_BN_P_normd[0]', 'v_BN_P_normd[1]', 'v_BN_P_normd[2]', 
         'battery_charge_fraction', 'target_obs.target_0.priority', 
         'target_obs.target_0.location_normd[0]',  'target_obs.target_0.location_normd[1]', 
         'target_obs.target_0.location_normd[2]',  'target_obs.target_1.priority', 
         'target_obs.target_1.location_normd[0]', 'target_obs.target_1.location_normd[1]', 
         'target_obs.target_1.location_normd[2]', 'target_obs.target_2.priority', 
         'target_obs.target_2.location_normd[0]', 'target_obs.target_2.location_normd[1]',
         'target_obs.target_2.location_normd[2]', 'normalized_time']

Type of change

• [ ] Bug fix (non-breaking change which fixes an issue)
• [X] 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
• [X] All changes at once

How Has This Been Tested?

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

Passes Tests

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

Test Configuration

• Python: 3.11
• Basilisk: 2.2.2
• Platform: MacOS

Checklist:

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