Unify handling of missing parameter(s)/option(s)

[JanKrivanek]

Current situation:

Some cases are handled by top-level parser in sdk as invalid comand (Example: #4787 (comment)), some are handled within templating with an paropriate exit code (Example:

templating/docs/Exit-Codes.md

Line 100 in c2f9202

_Examples:_

)

Expected behavior:

All cases of missing mandatory arguments or options will lead to same exit code. The handling should ideally be unified within the System.CommandLine Parser