JSON_v2 parser enhancement: zip values from two different arrays

There is a JSON style (albeit probably not an optimal one) that splits keys and values into separate arrays. A real world example is needing to pair keys in `"keys"` and values in `"values"` in the below JSON, such that the Line Protocol output gets pairs like `shortterm=0.83`:

_Note: it can be assumed that these will be ordered appropriately_
```
{
"keys": [
"shortterm",
"midterm",
"longterm"
],
"values": [
0.83,
1.76,
2.27
]
}
```

This is done in Starlark with `zip()` (snippet):
```
pairs = zip(dsnames, values)
for key,val in pairs:
if val == None:
val = float()
new_metric.fields[key] = val
```

Start by locating the JSON_v2 parser and its existing handling for arrays and field construction. Verify how ordered `keys` and `values` could be paired, then confirm completion by producing Line Protocol fields such as `shortterm=0.83` from the example input.

Written by the indexing model from the issue text.