Deleted a bunch of files which are unrelated to the parameter
optimization process as described in the article. The deleted
files include the following analysis:
- Frequency response related analysis
- Perturbator design
- Noise model simulations
- Symbolic sensitivity calculation
- etc.

Some of the functions may still be called in the core analysis,
which means we still have to remove some function calls in the
remaining code.

Spent: 1h