increased crate-admin version to 0.8.4
added parser support for insert from subquery
implemented insert by query analysis
added parser support for insert from subquery
implemented internal-only ``cast`` function
implemented insert by query analysis
added implicit type casting on insert with subselect
insert by query plan WIP
fix clusteredByColumn serialization in AbstractIndexWriterProjection
issue inserts on shard for insert-by-query without limit

- forbid insert by query with limit/offset or order by
Merge pull request #893 from crate/m/insert-by-query-plan

implemented insert-by-query plan
added docu for insert by query
fix itest flakiness and improve formatting
use doc lookup instead of field caches for normal select