Reopen: Added missing path types (AtsushiSakai#949)

* added missing RS path types

* modified assert condition in test3

* removed linting errors

* added sign check to avoid non RS paths

* Mathematical description of RS curves

* Undid debugging changes

* Added large step_size consideration

* renamed test3 to test_too_big_step_size

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Co-authored-by: Videh Patel <[email protected]>

Author: videh25