Improve Compose e2e tests by creating individual Onboarding pages

[xbabalov]

Is your enhancement related to a problem? Please describe

Compose onboarding consists of multiple pages, that all contain different constant elements specific to the corresponding page. Instead of locating the constants in the test itself using the same page model, we should create individual Onboarding pages for each step of Compose onboarding to ensure clarity, better organization and precision.

Follow up issue to: https://github.com/containers/podman-desktop/issues/4822

Describe the solution you'd like

Implement separate Onboarding page models for each Compose Onboarding step.

Describe alternatives you've considered

No response

Additional context

No response