fix(format): Fixed SQL view formatting issue not following SQLFluff recommandations

[Cedric-Magnan]

Problem

If the sql string variable in the relations/view/create.sql macro has multiple lines, the SQL view generated by dbt has one first line indented by 4 spaces, but the rest of the SQL code has no indentation.

This does not respect SQLFluff best practices for indentation : https://docs.sqlfluff.com/en/stable/layout.html#indentation

The indentation should be treated as a hint to the reader of the structure of the code.
This explains the common practice within most languages that nested elements (for example the contents of a set of brackets in a function call) should be indented one step from the outer elements.
It’s also convention that elements with the same level in a nested structure should have the same indentation, at least with regards to their local surroundings.

Solution

By adding the Jinja2 indent function :
https://jinja.palletsprojects.com/en/3.1.x/templates/#jinja-filters.indent

We are able to indent all content from the sql variable (except the first line which is already indented) !

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

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