Physics orbit workdone

[SajeevSenthil]

Describe your change:

• Add an algorithm
  To move an object from initial radius ri to final radius rf, the work done 𝑊 is:
  W = (GMm/2)*((1/ri)-(1/rf))

The file is placed in the physics/ directory and contains:

• Edge case handling (zero mass or radius)
• Doctests for validation
• Type hints
• Command-line interface for user input

No existing code was modified.

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Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, I have not included unrelated changes.
• All new Python files are placed inside an existing directory (physics/).
• All filenames are in all lowercase characters with no spaces or dashes (escape_velocity.py).
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
  (No direct link included as it's a standard textbook formula)
• This pull request does not resolve any open issues.