[Postgres] Avoid storing copy of replicated rows with REPLICA IDENTITY FULL

[rkistner]

When a table is configured with REPLICA IDENTITY FULL, a copy of the entire row is sent with every operation, avoiding any issues around TOAST values. This means we don't need to persist a copy of the raw data in the current_data collection - we can remove it for these tables.

Currently the logic for whether or not to store this is global based on the source database type - see logic here for example:

powersync-service/modules/module-mongodb-storage/src/storage/implementation/MongoBucketBatch.ts

Line 200 in b457d92

if (this.storeCurrentData && !this.skipExistingRows) {

We should make this more granular to support table-level config, to reduce storage requirements and potentially increase throughput.