[Scylla] - Fix batching logic

[jr1221]

Description

Batching logic has a max instruction set of 65535, and with 4 instructions per INSERT the batch has a max messages of 64435/4. We need to optimize splitting the batch inserts while continuing to obey the upsert time.

Acceptance Criteria

• New logic splits up inserts so there isnt any 1 item inserts

Proposed Solution

Split the items up using a division, where remainder is attached to one message, guarranteeing data over the limit wont be used.

Mocks

No response