dbt-core 1.2 upgrade: Cross-database Macros

[jlarue26]

From dbt-labs/dbt-core#5468:

In dbt-labs/dbt-core#5298, we migrated a collection of "cross-database macros" from dbt-utils to dbt-core. Default implementations are automatically inherited by adapters and included in the testing suite. Adapter maintainers may need to override the implementation of one or more macros to align with database-specific syntax or optimize performance. For details on the testing suite, see: "Testing a new adapter".

The TL;DR rationale for this work is:

Simplify dbt-utils development
Allow some packages to no longer depend on dbt-utils as a package
Provide adapter maintainers tests that can but used in the adapter repo CI, as opposed to in a shim package
As for how to make it happen, looking at the following PRs for dbt-Labs-maintained adapters show it clearly:

dbt-labs/dbt-bigquery#192
dbt-labs/dbt-redshift#120
dbt-labs/dbt-snowflake#162

[ravjotbrar]

Since, default implementations are automatically inherited by adapters and included in the testing suite, any issues related to these macros would become apparent when running the tests. All tests currently pass and any issues (including timestamp) were addressed in basic func tests. Closing.