Support for parsing lists in yaml-parse Promotion Step.

[bartpaczkows]

Hi,
The current implementation of the yaml-parse promotion step does not allow parsing YAML files that contain a list; only maps are supported. My proposed solution is to modify the readAndParseYAML function so that it always returns a map. If the parsed YAML file contains a list at the root, the function should wrap this list in a root element before returning the data structure.

For example, if our input YAML file looks like this:

- destination:
    name: demo1
    namespace: one
- destination:
    name: demo2
    namespace: two

The returned data should contain a "root" element, like so:

root:
- destination:
    name: demo1
    namespace: one
- destination:
    name: demo2
    namespace: two

By doing so, we will be able to use fromExpression statements such as the following:
filter(root, .destination?.name == "demo1")
which is currently not possible.

Please let me know if it makes sense to prepare such a Merge Request.

[krancour]

Isn't this the same thing as #5102?

Let's keep the conversation in just one place, please.

Closing in favor of #5102.