[CT-2819] default__alter_relation_add_remove_columns macro does not use quoting with case sensitive Snowflake relation

[McKnight-42]

associated with: dbt-labs/dbt-adapters#250
docs dbt-labs/docs.getdbt.com/#

Problem

user raised issue around "While working with DBT incremental config: on_schema_change='append_new_columns'
The append new columns flag is not able to capture the correct case-sensitive column name and add it to the incremental table causing the run to fail."

they stated they were using snowflake.

Solution

add a new test to dbt-adapters-tests to check that column quoting case sensitivity is expressed correctly, update all macros in adapters as needed if they do not use the default implementation and test default implementing macros to see if we need to update the dbt-adapters macro as well.

Todo:

• test with rest of adapters (see if dbt-adapter default version of macro needs to be changed or any other adapter override version of macro).
• make sure new tests works in all adapters as needed
• update requirements files either dev-requirements or project.toml files before merger

Checklist

• I have read the contributing guide and understand what's expected of me
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• This PR has no interface changes (e.g. macros, cli, logs, json artifacts, config files, adapter interface, etc) or this PR has already received feedback and approval from Product or DX