v1.5.0rc1

[arthurcht]

(on behalf of @nszoni )

Support for dbt-core 1.5

• Add support for model contracts by adapting create_table_as and create_view_as macros
• Define supported constraints in CONSTRAINT_SUPPORT Adapter class.
• Persist docs via extended properties is not supported in Synapse
• Add adapter tests zones
  • caching
  • column_types
  • constraints
  • hooks
  • simple_copy
  • dbt_show

base branch from #191