fix: in star make excludes a list

[jasnonaz]

This is a:

• [ X] bug fix PR with no breaking changes — please ensure the base branch is master
• new functionality — please ensure the base branch is the latest dev/ branch
• a breaking change — please ensure the base branch is the latest dev/ branch

Description & motivation

The feature added in 0.7.2 which allowed for star excludes to be case insensitive appears to have brought in an issue causing columns to get incorrectly dropped. #417

It looks like this is due to the |lower command turning a list into a string - this fixes that by looping over the columns to exclude and lowercasing them individually.

Checklist

• I have verified that these changes work locally on the following warehouses (Note: it's okay if you do not have access to all warehouses, this helps us understand what has been covered)
  • [ X] BigQuery
  • Postgres
  • Redshift
  • Snowflake
• I have "dispatched" any new macro(s) so non-core adapters can also use them (e.g. the star() source)
• I have updated the README.md (if applicable)
• I have added tests & descriptions to my models (and macros if applicable)
• I have added an entry to CHANGELOG.md

[clausherther]

FYI, I think another way to do this with looping and explicitly creating a new list would be something like

set cols = cols | map("lower") | list
set except = except | map("lower") | list

[wuservices]

FYI, I think another way to do this with looping and explicitly creating a new list would be something like

set cols = cols | map("lower") | list
set except = except | map("lower") | list

@clausherther Is | list necessary?

Could you just change from |lower to |map('lower') i.e. from

{%- if col.column|lower not in except|lower -%}

to

{%- if col.column|lower not in except|map('lower') -%}

Playing around a little, this seems to work.

[reidwil-jb]

I appreciate the quick solutions on my first commit and subsequently first bug. 🐛