Scrapping Scaladex should support dynamically generated data

[WojciechMazur]

Content of Scaladex versions matrix is not a static page - the content is being dynamically generated upon scrolling the page. For most of the projects that are not an issue, however, Scaladex can also contain snapshot version entries (scalacenter/scaladex#927) for which we should not run the build as they're not stable, and we accept only official (pre-)releases.
If the project contains a lot of snapshots we might not be able to get the last official release in the initial results scrapped using JSoup, (we have that problem with http4s) and though would be not able to resolve names of the artefacts produced by the given version. It would also lead to building a project using main branch, instead of using stable state assigned to given version tag.