generate_surrogate_key macro adds unnecessary empty lines before the code

[akv-akv]

Describe the bug

generate_surrogate_key macro adds unnecessary empty lines before the compiled code. These empty lines cause fails of sqlfluff linting.

Steps to reproduce

1. Create a model with the following code:

SELECT
    1 AS COLUMN_1,
    2 AS COLUMN_2,
    {{ dbt_utils.generate_surrogate_key(['COLUMN_1', 'COLUMN_2']) }} AS PK_ID

2. Compile this model

Expected results

Compiled code should look like this:

SELECT
    1 AS COLUMN_1,
    2 AS COLUMN_2,
    md5(cast(coalesce(cast(COLUMN_1 as TEXT), '_dbt_utils_surrogate_key_null_') || '-' || coalesce(cast(COLUMN_2 as TEXT), '_dbt_utils_surrogate_key_null_') as TEXT)) AS PK_ID

Actual results

The actual compiled code looks like this:

SELECT
    1 AS COLUMN_1,
    2 AS COLUMN_2,
    
    
md5(cast(coalesce(cast(COLUMN_1 as TEXT), '_dbt_utils_surrogate_key_null_') || '-' || coalesce(cast(COLUMN_2 as TEXT), '_dbt_utils_surrogate_key_null_') as TEXT)) AS PK_ID

Screenshots and log output

System information

The contents of your packages.yml file:

packages:
  - package: calogica/dbt_expectations
    version: 0.8.2
  - package: dbt-labs/dbt_utils
    version: 1.0.0
  - package: dbt-labs/codegen
    version: 0.9.0

Which database are you using dbt with?

• postgres
• redshift
• bigquery
• snowflake
• other (specify: ____________)

The output of dbt --version:

Core:
  - installed: 1.3.0
  - latest:    1.3.2 - Update available!

  Your version of dbt-core is out of date!
  You can find instructions for upgrading here:
  https://docs.getdbt.com/docs/installation

Plugins:
  - snowflake: 1.3.0 - Up to date!

Are you interested in contributing the fix?

Yes, I'm interested in contributing. The local tests showed that the problem can be solved by adding whitespace control to the macro code https://github.com/dbt-labs/dbt-utils/blob/main/macros/sql/generate_surrogate_key.sql
If lines 7 to 11 of the macro code look like in the example below dbt compile produce the expected results:

{%- if var('surrogate_key_treat_nulls_as_empty_strings', False) -%}
    {%- set default_null_value = "" -%}
{%- else -%}
    {%- set default_null_value = '_dbt_utils_surrogate_key_null_' -%}
{%- endif -%}