nodbi v0.10.2

Changes

• added vignette
• added tests internal functions, verbose option
• added caching to GitHub action workflow
• added missing fields validity check for duckdb
• more robust parameter checks in docdb_query and docdb_update
• ensure NULL also for all MongoDB returns

Bug fixes

• docTyp'ed src.R
• minify JSON with Elasticsearch in docdb_update
• moved local variable out of UseMethod in docdb_query