Hydrilla

change file path format

From now on we'll be using format 'file/sha256/' instead of 'file/sha256-'.

include new schemas in package and in tests

fix typing mistake i tests

facilitate for including other schemas in submodule and expose them to other packages

move to a namespace package under 'hydrilla'

test&fix error handling

add test case with modified index.json from the example

extend the automated test case

initial commit