Support path-wildcards ($append, $prepend, $last, $first) for whole objects

[TobiasNx]

Adding and copying sub-fields with $append seem to work. But copying and moving whole objects into an array with $append seems not to work:
https://gitlab.com/oersi/oersi-etl/blob/2a05f299ebb6346cf59b4d1ad7b8930531a9a834/data/experimental/appendArrays/test_append_object.flux

See here in the Playground too

Originally posted by @TobiasNx in #80 (comment)

It is related to MR #87 and issue #82 (but for strings) which deals with appending.
If we decide that this should be solved in another MR we should exclude the failing test for complex appending objects.

{
	"animals":[
			{"animal": "dog"},
			{"animal": "cat"},
                        {"animal": "human"},
                        {"animal": "unicorn"},
                       {"animal": "earthworm"}
	],
	"others":  {"animal": "human"}
}

[fsteeg]

See also this example from #94 (comment).

[TobiasNx]

See test: TobiasNx/fix-FunctionalReview-Testing@a45d39c

Expected:

{
	"animals":[
			{"animal": "dog"},
			{"animal": "cat"},
			{"animal": "human"},
			{"animal": "unicorn"},
			{"animal": "earthworm"}
	],
	"others": {"animal": "human"}
} 

Is:

{
  "animals" : [ {
    "animal" : "dog"
  }, {
    "animal" : "cat"
  }, {
    "animal" : "earthworm"
  } ],
  "others" : {
    "animal" : "human"
  }
}

[TobiasNx]

Added also a prepend function to test: https://github.com/TobiasNx/fix-FunctionalReview-Testing/tree/master/data/testing/appendArray_objects

[fsteeg]

Will revisit after #102.

[blackwinter]

Integration tests:

• copy_fieldPrependObjectToArrayOfObjects
• move_fieldPrependObjectToArrayOfObjects