style(yaml): preserve newlines in folded block scalars

[eric-thelin]

From the official documentation of yamlfmt:

Option that will preserve newlines in folded block scalars (blocks
that start with >).

Without this option newlines in folded block scalars are always replaced with spaces. This defeats the purpose of using a folded block scalar.

Consider this YAML:

example_of_folded_block_scalar: >
  Lorem ipsum dolor sit amet,
  consectetur adipiscing elit,
  sed do eiusmod tempor incididunt
  ut labore et dolore magna aliqua.

The above is an example of a folded block scalar (as denoted by the > syntax). It is a way to break a long string into multiple lines for better readability. The newlines are interpreted as spaces.

However, without scan_folded_as_literal: true the linter would replace the newlines with spaces and place the whole text on a single line:

example_of_folded_block_scalar: >
  Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.

This is counterproductive. If I wanted to put the whole thing on a single line, I would use a regular string and not a folded block scalar.

See: https://yaml.cc/tutorial/yaml-multiline-string.html
See: https://github.com/google/yamlfmt/blob/main/docs/config-file.md

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