[MC-138106] /data modify doesn't create a list item if it can't find any

The bug

When you use `/data modify` and it doesn't find the thing specified in the path, it creates that tag. However, if that path contains a list (that doesn't exist) with an index, it doesn't create the list.

How to reproduce

Set a chest with an item

/setblock ~1 ~ ~ minecraft:chest{Items:[{Slot:0b,Count:1b,id:"minecraft:dirt"}]}

Try to give the item lore by `set`ting `Lore[0]`, this fails because the `Lore` list doesn't exist
```
/data modify block ~1 ~ ~ Items[0].tag.display.Lore[0] set value "\"hi\""
```