Use our own measurements

[jeanbarrossilva]

Replaces usages of measurements from the Foundation framework by those of Deus. This has been attempted before in the project, but the effort of implementing and maintaining measurements of our own did not seem reasonable at the time; therefore, the decision made was to resort to those provided by Apple by default (#25).

However, the work done on #40 and #52 has shown that measurements with very specific units will be required by the application, and these are not provided by the framework by Apple (e.g., measurements of action in eV/eV⁻¹ or in J/s). To prevent resorting to the context in which the variables are declared/referenced to and having them store plain numeric values, such as

let c = 299_792_458

a protocol to which these "custom" measurements conform or can conform to has been declared in the QuantumMechanics framework, given that such framework is the origin of the necessity of measuring in the dependency tree.

The measurements implemented in this PR are those equivalent to those from the Apple framework which were being used up until this moment in the project. Any other implementations to be required by future or parallel work may be added in the PR related to such work. Implementations included in this one are:

• Angle;
• ElectricCharge;
• Mass; and
• Speed.