Refactor holes

[Ruudjhuu]

Refactor some hole creation which makes code more readable and is more than 4x faster.

My goal is to add some more small improvements so:

• low level functions don't need high level knowledge (a function that creates a shape of a hole should not have the knowledge to copy it in an array on specific locations. This improvement should improve re-usability)
• Remove the use of freecad.DocumentObject as much as possible as this makes it hard to test. (creating a cylinder with height and radius is more readable and logic than a creating it with a DocumentObject argument.

[greg19]

Did you look at changes in #116? It makes a lot of changes for magnet holes. It is almost finished, I need to test the magnet removal holes and tweak the numbers there. Apart from that the code shouldn't change.

[Ruudjhuu]

nope, did not see it. Seems like this is obsolete now.