create domain model for ide-urls

[hohwille]

For our epic #941 we have decided to do the implementation in Java what is way more maintainable compared to bash.
This story is about implementing the "domain model" for the different elements of the ide-urls repository:

• UrlRepository for the root
• UrlTool for a specific software tool (java, gradle, etc.)
• UrlEdition for the edition of a specific tool (e.g. rancher or docker for docker as well as ultimate or community for intellij)
• UrlVersion for a version of a specific tool edition
• UrlFile for the actual *urls file containing one or multiple download URLs.
• UrlStatus for the status.json file with the status metadata.