INSERT INTO .. RETURN <EXP>

Since now INSERT command has additional keyword RETURN used with expression (similarly to #2319 )

``` SQL
INSERT INTO [class:]<class>|cluster:<cluster>|index:<index> [(<field>[,]*) VALUES (<expression>[,]*)[,]*]|[SET <field> = <expression>|<sub-command>[,]*]|CONTENT {<JSON>} [RETURN <expression>] [FROM select-query]
```

The command may return created documents, specified field or record attributes. Below you may find couple of examples:

``` SQL
// returns new record
INSERT INTO Actor2 SET FirstName="FFFF" RETURN $current
INSERT INTO Actor2 SET FirstName="FFFF" RETURN @this

// returns only new records rid.
INSERT INTO Actor2 SET FirstName="Butch 1" RETURN @rid

//returns collection of rids
INSERT INTO Actor2(FirstName,LastName) VALUES ('Jay','Miner'),('Frank','Hermier'),('Emily','Saut')  RETURN @rid

//Create records by INSERT INTO ...FROM and return wrapped field „FirstName”
INSERT INTO Actor2 RETURN $current.FirstName  FROM SELECT * FROM [ #12:2,#12:3 ]

// example of usage in sql batch when new Actor2 record is created and @rid is assigned to variable
// This record id is provided then to UPDATE as a target record. 
let var1=INSERT INTO Actor2 CONTENT {Name:"content"} RETURN $current.@rid
let var2=UPDATE $var1 SET Bingo=1 RETURN AFTER @rid
return $var2
```