feat: enabling structured package

[clatapie]

This PR modifies the structure of the created package.

Structure of the package before:

repository
  |  function1.py
  |  function2.py
  |  function3.py
  |  function4.py
  |  function5.py
  |  function6.py

Now:

repository
  |  module1
  |    |  class1.py
  |    |    |  function1
  |    |    |  function2
  |    |    |  function3
  |    |  class2.py
  |    |    |  function4
  |    |    |  function5
  |    |    |  function6

This new structure is directly obtained from the XML repository.

TO DO:

• fix tests
• clean up the code

[germa89]

Several comments.

• Avoid generate the content at the same time you write the file, so you can test the content without writing the file.
• You do not need to use fid.close if you are working inside a context manager.
• Readability is important. Please group statements doing an specific function, under a function with proper name. Sometimes the code is difficult to follow if you have many many statements doing "standard" python (not grouped in functions). I mean, you either comment more your code, so we know what is doing each block of statements, or you group that block under a function with a representative name.

[clatapie]

Thank you very much for your review @PipKat!

[germa89]

Just a minor remark. Other than that, I trust my past self. xD

[RobPasMue]

Overall LGTM but as you may imagine, I couldn't review in depth all the logic. Left some comments. Request review once solved.

[clatapie]

Type hint has been implemented in most of the package - except in the ast_tree.py module.

[RobPasMue]

LGTM! Thanks @clatapie for your hard work on this