cwclientlib #5169115 move sources in a package drectory [validation pending]

to follow current recommendations from the pypa project and be 'pip install -e' compatible

prioritynormal
typetask
done in0.3.0
load0.250
load left0.000
closed by#23bc577362d0 [pkg] change project layout so the main directory is no longer a package (closes #5169115)
patch[pkg] change project layout so the main directory is no longer a package (closes #5169115) [applied]