Create a pipeline unit which recommends using Thoth's s2i

[fridex]

Is your feature request related to a problem? Please describe.

As we will soon bring #1632 it might be good to let the recommendation engine suggest to use Thoth's s2i base image. Besides suggesting it, we should state why Thoth's base s2i image should be used and what are all the advantages of doing so.

Describe the solution you'd like

Implement a pipeline unit that suggests using Thoth's s2i base container images if users do not use them already.