Support resolving referenced files when building a factory from a link to raw content of the devfile

[metlos]

Description

Currently when creating using the factory to build a workspace from a link to a devfile content, the "links" to other files using the local attribute are not supported.

This could be improved and we could leverage the hierarchical nature of the URL to the devfile to try an locate those files.

This will of course still fail in cases like similar to "Test 3" in #12278 where the url to the devfile is not the same as to the rest of the codebase (e.g. https://pastebin.com/raw/d4wty8Q1) but it would work in a case where the URL would point to a view of the repository, like for example https://raw.githubusercontent.com/che-incubator/chectl/master/.devfile