Add model of horizontally rotating arm

[1-Bart-1]

Moving the following issue here.
https://github.com/ufechner7/KiteModels.jl/issues/237#issue-3178235870

The following steps are needed for implementing the horizontally rotating arm:

[abavoil]

Some complements from my notes:

• for Winch.type = Arm, remove the drum part and add a (list of) point(s) attach_point_idx(s) which are the tip(s) of the arm(s), to be specified when building the model. Throw error if attach point is not of type rigid body
• modify the equations of the winch calc_acceleration(speed, force) -> calc_angular_acceleration(angular_speed, torque), and put them into SymbolicAWEmodels.jl