Include Eigen C++ Library for Matrix Operations in Unity

[leebissessar5]

Objective:
To integrate the Eigen C++ Library into the Unity framework for efficient matrix operations and advanced mathematical functionalities.

Background:
Unity lacks an efficient and transparent mechanism for intricate matrix operations. The Eigen C++ Library is widely used in high-performance applications, including TensorFlow and DART Physics. The inclusion of Eigen will bring transparency and reliability, which are vital for precision and repeatability in simulations, a shortfall observed in libraries like MathNet (which has been tried previously but was unsuccessful due to NuGet inconsistencies with Unity).

TODOS: (Do not tick unless there is an associated passing unit test)

• [x] Implement base constructor for a 1D array with column and row-major options (see 3a8687e)
• [x] Implement constructor for a 2D array (see 23d607c).
• [x] Implement function that formats a matrix to string
• [x] Implement matrix multiplication
• [x] Implement transpose (in place and copy) (see 0561b15)
• [x] Implement matrix addition and subtraction (see ae8b3fe)
• [x] Implement equality operators (see 0c28743)
• [x] Implement ordinary inverse (see d62cc11)
• [x] Implement identity (see 388b5cf)
• [x] Implement scalar multiplication (see a1c55c6)
• [x] Implement conversions to 1D and 2D arrays (see 78438d2 for 1D, 16b8821 for 2D)
• [x] Implement copy constructor (see 23b2516)

Exceptions Exception handling is not needed at this stage in the interest of deadlines. However, at a later point in time, it will be mandatory to implement.

Deliverables:
A robust integration of the Eigen C++ Library into Unity, enabling high-performance matrix operations, enhancing algorithm efficiency, and paving the way for advanced mathematical and physics-based simulations in the Unity environment.

[leebissessar5]

All tasks have been completed, this will be merged into quadcopter-simulation.