[INPUTS/OUTPUTS] Formalization of requirements and contracts for ODAHU services inputs, description of outputs

[alinaignatiuk]

Create a list of required inputs for ODAHU services (and formats that are currently supported in ODAHU for each input) and outputs that ODAHU services produce (and formats that are currently supported in ODAHU for each output).
Specify for each input whether it is mandatory for ODAHU service (the ODAHU service will not be able to perform the work without it) or non-mandatory/optional.
The purpose of this list is to:

1. Create visibility for users on how the ODAHU system operate and what are the requirements and supported formats;
2. Create the dev plan for required improvements in the validation process in ODAHU: what kind of validation should be performed, so that the ODAHU will not crash if the obligatory inputs are not in place, but rather inform the user about missed requirements.

[alinaignatiuk]

Connected with #609