This is needed as we get software instances by their reference and not
their relative urls

slapos_jio_api_style: Add related key to be able to search instance from host compute node reference

* NotFound Errors are now handled by API

Can replace the following SlapTool calls:
* softwareReleaseError
* availableSoftwareRelease
* buildingSoftwareRelease
* destroyedSoftwareRelease

slapos_accounting: calculating the outstanding deposit amount need to also check the balance which include the VAT

Test: ensure a second service can be ordered

so that we can click on the link

   If a software instance with 1 or more slave instances allocated on it is destroyed the instances aren't reallocated, so let's create a ticket to high light the problem.