Improve query performance

[fcasson]

• Queries on arbitrary metadata fields from CLI should pass a proper DB query directly to the server
• Current implementation communicates all metadata (minus file metadata) and is not scalable to large databases
• SQLAlchemy has known performance issues for large databases, see e.g. https://docs.sqlalchemy.org/en/14/faq/performance.html#result-fetching-slowness-core and SimDB may need an API to communicate directly with SQL.
• Example: For a large database of 20,000 entries, simdb remote list -l 0 takes about 4 seconds, however requesting metadata takes longer, e.g. simdb remote list --limit 0 -m userid -m codeid -m machineid -m shotid -m dateid -m seqid takes 20s.

Internal link: https://git.ccfe.ac.uk/jintrac/jams/-/issues/93