Restructure examples

[ccicconetti]

Currently, the examples directory contains workflows, with nested functions.

What about restructuring the directory so that we have the following?

examples/workflows/
examples/functions/

Pro:

• The functions directory would act as a sort of mini-repository of example functions, to be seamless used across example worfklows.

Con:

• We will have to use parent directory references in the include_code_file JSON fields of workflows, instead of local references.