Support JSON file upload for bulk insert of records

[kdhrubo]

Discussed in #612

^{Originally posted by kdhrubo May 8, 2024}

1. Max file size of 5MB to be supported.
2. This will be an async operation.
3. Records will be streamed in chunks.

[Hackeemlunar]

Must the chunks be processed immediately or one can wait for the whole file to be built

[kdhrubo]

Please explain what do you mean?
Ideally it should be chunk based processing

[thadguidry]

Chunks should be processed as received.
One has to consider that someone MIGHT want to upload a 4gb JSON string into a DB column?
But I guess for this issue we can start with a maxFileSize = 5MB

Questions:

1. Whatever we do, for JSON processing anywhere in DB2Rest, we should never use org.json (which still has licensing issues) but instead com.fasterxml.jackson.core?
2. Perhaps we should expose a new parameter to allow specifying which JSON datatype is going to be used for the prepared statement insert? (PostgreSQL has json and jsonb and I have needed json to keep things exact and retain key ordering, but then other times needing jsonb so that indexing could be used for efficient, fast, jsonpath queries later on.)

[Hackeemlunar]

@kdhrubo I get it now.

@thadguidry The file upload insertion is already a type of bulk insertion. Bulk insertion currently happens on **/db/{tablename}/bulk, so what **/db/{tablename}/file endpoint for the file processing?

[kdhrubo]

Instead of file make it upload pls