Dbt-ibmdb2

- Filter only non-hidden columns from DB2 metadata table

- Added option for setting seed batch size
- Bugfix in incremental materialization
- Make test run faster by running tox in parallel mode

Thanks to contributor mikaeltw !

- Changes the exceptions
- Restructure of timestamp macros + adds timestamp test case
- Changes the dbt dependency to ~1.4 instead of ^1.0.0
- Fixes a bug with dbt now expecting a default_factory function for quote_policy and include_policy in IBMDB2Relation
- Improved readiness check for the Db2 container to speed up the testing on some machines
- Bugfix in README
- Change version naming to follow dbt-core

Thanks to contributor nielspardon!

- Add config option for table distribution

- Remove Python 3.10 from pyenvs (ImportError)
- Small fix in incremental model

- Bugfix - cannot revoke and grant in the same transaction