MRO tracking file reading example

[simon-van-hulle]

This pull request contains a simple first example to read observations from a .txt file

• MRO 2-way range readings are read and processed
• The same observations are calculated from SPICE kernels. This is done first with default settings, then with an improved rotation model and finally with first-order light time correction to show how this improves the residuals.

Please note that the latest code from this tudat pull request is needed to run the example