Zero downtime tracelistener bulk imports

[Pitasi]

DoD:

• make bulk import use Upsert queries version instead of Insert (we could add a flag to decide, because plain INSERTs runs much faster in cockroach)
• after the bulk import is done here, run a logic that deletes all rows from all the known table that have the height column lower than the bulk import height
• add new unit tests to test corner cases (newer data already present in db, or older data present in db, or a mix of both)

Important notes about deleting many rows at once:
Running a single DELETE FROM xxx WHERE height < yyy is not sufficient. It fails in cockroachdb when there are too many rows to be deleted (docs).

What must be done is to re-use the "chunked delete" logic contained in the reset-chain binary, maybe moving it into a shared go pkg.