Change transform.py to numpydoc style

[KybernetikJo]

This PR refactors the Slycot/slycot/transform.py in order to be closer to the numpydoc style as discussed in #100.
Should be part of #204.

(finished 12 of 12 routines)

Routine name	Finished	Status description
tb01id		*3
tb10pd		*3
tb03ad		*3
tb04ad		*3
tb05ad		*3
tc01od		*3
tc04ad		*3
td04ad		*3
tf01md		*3
tf01rd		*3
tf01rd		*3
tf01rd		*3

Status description:

1. numpydoc docstring sections, fixed
2. parameters data types, fixed and 1 fixed
3. optional and default values, fixed and 2 fixed

[KybernetikJo]

This PR splits the tests/test_transform.py file into single files, one file for a subroutine/function.

There is a comment in test_transform.py:

#
# test_transform.py - generic tests for transform routines
# repagh <rene.vanpaassen@gmail.com, May 2020

• How should we handle such comments if the file structure changes?
• It is an info not a copyright, right?
• Should we copy such comments into every new file?

[bnavigator]

Technically it is a copyright, but the license is missing. Please copy it over, but as said in #206, don't go overboard with the file count.