Change directory of sort algorithms

[Sumith1896]

All the sort algorithms currently reside in pydsa/, move them to sorting/
Inside this we can have all the sorting algorithms in separate files as we have now else we can have them in one file.

[aktech]

Yes, that would be better now, since the number of files were less, I had kept them in one file.

[manu-chroma]

Hi, looks like there is no progress in PR #82 regarding this issue.

If no one has taken this issue, I can complete this task and fix any failing tests accordingly.