Add config utilities for processors and connectors

[lovromazgon]

Description

This PR creates package config and moves over code from the connector SDK regarding config parameters and validations. Some things are slightly refactored, but generally, the functionality stays the same.

This also adds a proto file for the parameter definitions. The idea behind this is that it will allow us to reuse the same code in the connector and processor SDK. Additionally, this package will allow us to reuse the same paramgen tool in connectors and processors.

Quick checks:

• I have followed the Code Guidelines.
• There is no other pull request for the same update/change.
• I have written unit tests.
• I have made sure that the PR is of reasonable size and can be easily reviewed.

[hariso]

🚀