Proper build + runtime error handling and exposure

[RomanYarik]

Currently the error handling in the engine, and how it is being projected to the user, doesn't help the users understand what is wrong/missing/more, and it causes frustration when using the product.

We need to document proper usage as well as locate all possible user pitfalls and provide proper warn/error messages to the user. At build time we can think about the conventions defined by engine-scripts/engineer and enforce/validate the user defined everything properly (feature names, .env/feature/context files are named properly, missing setup files and more). At runtime we have many errors (unknown topology error for example) which doesn't really explain what the user is doing wrong. Also proper validation and and error messages will reduce frustration