Fix bug with calculation of last_run stats for incremental models

[glsdown]

Overview

As noted in #372 the way that last_run_* stats are calculated in dim_dbt__current_models is incorrect. This aims to fix them, as well as provide 4 additional fields:

• last_incremental_run_completed_at
• last_incremental_run_total_runtime
• last_incremental_run_rows_affected
• last_incremental_run_bytes_processed - BQ only

Update type - breaking / non-breaking

• [x] Minor bug fix
• [ ] Documentation improvements
• [ ] Quality of Life improvements
• [ ] New features (non-breaking change)
• [x] New features (breaking change)
• [ ] Other (non-breaking change)
• [ ] Other (breaking change)
• [ ] Release preparation

What does this solve?

• Resolves #372

Outstanding questions

What databases have you tested with?

• [x] Snowflake
• [x] Google BigQuery
• [x] Databricks
• [ ] Spark
• [ ] N/A