Add Number of Orbit and Fraction of Orbit Triggers

[AlexCarpenter46]

Proposed changes

Adds a trigger to do something the user specifies after a certain number of orbits. Addresses #5938

If you want to try either of these triggers out for something like eccentricity control or Observations at certain points in. your orbit, add this to the EventsAndTriggers sections in your yaml.

  - Trigger:
      NumberOfOrbits:
        Value: 1.0
    Events:
      - Completion

  - Trigger:
      FractionOfOrbit:
        Value: 0.25
    Events:
      - ObservationAhA
      - ObservationAhB

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Code review checklist

• [ ] The code is documented and the documentation renders correctly. Run make doc to generate the documentation locally into BUILD_DIR/docs/html. Then open index.html.
• [ ] The code follows the stylistic and code quality guidelines listed in the code review guide.
• [ ] The PR lists upgrade instructions and is labeled bugfix or new feature if appropriate.