add OSD database and SC snapshot

[brownag]

• Add clone step to Docker build GitHub Action for OSDRegistry and SoilKnowledgeBase repos
• [ ] Copy OSDRegistry folder and SoilKnowledgeBase folder to /home/rstudio for easy access in Docker image? Or should they be stored in some other format? Could take the JSON files from SoilKnowledgeBase plus the SC database and dump into an SQLite file. This could be an artifact of the weekly SKB build and then we would just download that and dump it in the ldm_data_dir() directory Add download of SQLite OSD artifact RE: https://github.com/ncss-tech/SoilKnowledgeBase/issues/73

[brownag]

Now that space issues resolved in #3 this should be workable--not that the OSDs or SC take up that much space