Runtime: improve variable parsing and Builder array plucking

[JohnathonKoster]

This PR improves variable parsing (which allowed for some cleanup/simplifying of the NodeProcessor 🎉), which made it easier to correct a few issues with array plucking and query builders.

When assets is a Builder, this will now work as expected (the Builder instances are not sent through the query tag since they are treated as arrays)

{{ assets.2 }}
    {{ url }}
{{ /assets.2 }}

{{ assets[some_index] }}
    {{ url }}
{{ /assets[some_index] }}

If the final part of the variable path returned a Builder instance (regardless of how many parts/nested the variable path was), those instances are now sent through the query tag, making the following work:

{{ nested.level_two:level-three.1.assets order_by="field_name:desc" }}
     {{ url }}
{{ /nested.level_two:level-three.1.assets }}

To reproduce the issues resolved:

• Plucking issue: Create any field type that returns a Builder (assets, terms, etc.) and attempt to use a tag pair from array plucking ({{ field.0 }} {{ /field.0 }}
• Final Path Issue: Create a nested variable where the final part of the variable returns a Builder ({{ nested.field.builder }} {{ /nested.field.builder }})

More information that lead to this PR is here: #5881

[mikemartin]

@JohnathonKoster I ran into this issue when using offset and limit on an asset tag, will this PR address those parameters too?

{{ photos offset="1" limit="2" }}
...
{{ /photos }}

[JohnathonKoster]

@JohnathonKoster I ran into this issue when using offset and limit on an asset tag, will this PR address those parameters too?

{{ photos offset="1" limit="2" }}
...
{{ /photos }}

That seems like it may be a separate item entirely - I can do some testing on my end to see what may be going on - do you have any additional details about the issue?

Thanks!

[mikemartin]

Hey @JohnathonKoster
Just that it returns the images in the wrong order.

[JohnathonKoster]

@mikemartin Is this the kind of behavior your are seeing/referring to? If so, this is not related (and is consistent across both parser implementations).

[jasonvarga]

Assets in the wrong order is a weird one, and it happens to me too, but is separate from this issue 👍

[jasonvarga]

@mikemartin I'm fixing that in #5381