Allow array-type entity fields to have default values

[Gamer-XP]

Right now, you can create array fields for entities. Their editor looks the same as for normal fields, including setting default values. But this field got 2 issues:

1. It's ignored when adding entity to the level - newly created entity always got an empty array. That value is saved in json though.
2. You can only set single value, even though it's an array.

What I expect:

1. Be able to set any number of elements as default array for the entity, and this array to be set as default value for entities in the level editor.
2. When overriding array in the level - it overrides array as a whole, making a copy of it.
3. Optional: Add "Mask" flag for enum-type arrays. In this mode it will display the field as a list of toggles where you can enable/disable certain values from given enum. Examples: