ENH: adding rocket radius to RailButtons class

[juliomachad0]

Pull request type

• [X] Code changes (bugfix, features)

Checklist

• [X] Lint (black rocketpy/ tests/) has passed locally
• [X] All tests (pytest tests -m slow --runslow) have passed locally

Current behavior

A small change (addition of the rocket_radius attribute) was made to the RailButtons class to resolve issue #606. For the change to work in practical simulations, small changes were made to the rocket.py (add_surfaces method) and flight.py (u_dot_generalized method) files.

New behavior

It is now possible to use the RailButtons class in the way the user tried, without major changes to the code and with everything apparently working.

Breaking change

• [X] No

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 54.54545% with 5 lines in your changes missing coverage. Please review.

Project coverage is 75.69%. Comparing base (d977fbe) to head (ad67701).

Files	Patch %	Lines
rocketpy/rocket/rocket.py	33.33%	4 Missing :warning:
rocketpy/simulation/flight.py	66.66%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #643 +/- ## =========================================== - Coverage 75.72% 75.69% -0.03% =========================================== Files 81 81 Lines 9815 9823 +8 =========================================== + Hits 7432 7436 +4 - Misses 2383 2387 +4 ```

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