crud: support `operation_data` in errors

[oleg-jukovec]

We need to support a field named operation_data in errors from crud's *many* requests. The field can contain:

• tuple for which the error occurred;
• object with an incorrect format;
• tuple the operation on which was performed but operation was rollback;
• tuple the operation on which was not performed because operation was stopped by error.

It would be nice to have an ability to decode the tuple/object into a custom type with crud.Result helper type:

go-tarantool/crud/result.go

Lines 52 to 57 in b17735b

	// Result describes CRUD result as an object containing metadata and rows.
	type Result struct {
	Metadata []FieldFormat
	Rows interface{}
	rowType reflect.Type
	}