BQ init script runs deletions first

[gaborvolczer]

see BigQueryExecutor.executeBQInitializatorScript
deletions and inserts are collected from the script and run parallel, deletions first, inserts after

problem is that the script might contain other queries, for example "truncate"
other problem that statements might depend on each other
I think the best solution would be to keep the original sequence and forget parallelism here. ( but to be discussed)

Related PR: https://github.com/aliz-ai/jarvis/tree/cleanup_before_trivago_intergation | https://reviewable.io/reviews/aliz-ai/jarvis/45/examples/sample_volczi/volcziTest/case1/pre/volcziTest.sql

[nbali]

if we really need parallelism, it should be done with having multiple files (queryPath) containing the initialization -> parallel execution of files, but serial execution of statements inside a file