move dbt-exasol-utils into this repo - to combine tests and qa

[tglunde]

integrate shim package defs and docs into main dir/module

add integration-tests as pytest

[tglunde]

@mikhail-zhadanov any thoughts / counter-arguments?

[mikhail-zhadanov]

Hi @tglunde , please feel free to decide.
I wasn't sure about it - that's why I've created it as a separate repo.

Cons:

• dbt exasol repo will be bloated with code
• increased test complexity
• harder to deploy to https://hub.getdbt.com/ as it expects packages and not connectors (but maybe we don't need)

Pros:

• easier for users
• all code in one place