feat: thanos support

[Serpentiel]

About this change—what it does

• Add Thanos resource (aiven_thanos) to allow for the creation and management of Thanos services

Why this way

🚀

[byashimov]

I have created Thanos in the Console, it has connection info fields:

I believe we should proxy them to the resource.

[Serpentiel]

Temporarily marked as draft. Some things should be clarified.