Replace generic `Exception`s with more specific or ROHD-related exceptions

[mkorbel1]

Motivation

Many exceptions in ROHD are just Exception, but they should be more specific types of exceptions or ROHD-specific Exceptions.

Desired solution

Add new ROHD-specific Exceptions where applicable, and use existing Exceptions where possible.

[quekyj]

Hi Max, I will pick up this issue as well.

[mkorbel1]

It's also worth considering which should be errors vs exceptions: https://stackoverflow.com/questions/17315945/error-vs-exception-in-dart