[feature-wip](array-type)Add element_at and subscript functions (#8597)

Describe the overview of changes.
1. add function element_at;
2. support element_subscript([]) to get element of array, col_array[N] <==> element_at(col_array, N);
3. return error message instead of BE crash while array function execute failed;

element_at(array, index) desc:
>   Returns element of array at given **(1-based)** index. 
  If **index < 0**, accesses elements from the last to the first. 
  Returns NULL if the index exceeds the length of the array or the array is NULL.

Usage example:
1. create table with ARRAY type column and insert some data:
```
+------+------+--------+
| k1   | k2   | k3     |
+------+------+--------+
|    1 |    2 | [1, 2] |
|    2 |    3 | NULL   |
|    4 | NULL | []     |
|    3 | NULL | NULL   |
+------+------+--------+
```
2. enable vectorized:
```
set enable_vectorized_engine=true;
```
3. element_subscript([]) usage example:
```
> select k1,k3,k3[1] from array_test;
+------+--------+----------------------------+
| k1   | k3     | %element_extract%(`k3`, 1) |
+------+--------+----------------------------+
|    3 | NULL   |                       NULL |
|    1 | [1, 2] |                          1 |
|    2 | NULL   |                       NULL |
|    4 | []     |                       NULL |
+------+--------+----------------------------+
```
4. element_at function usage example:
```
> select k1,k3 from array_test where element_at(k3, -1) = 2;
+------+--------+
| k1   | k3     |
+------+--------+
|    1 | [1, 2] |
+------+--------+
```

be/test/vec/function/function_array_element_test.cpp

@@ -0,0 +1,84 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#include <gtest/gtest.h>
+#include <time.h>
+
+#include <string>
+
+#include "function_test_util.h"
+#include "runtime/tuple_row.h"
+#include "util/url_coding.h"
+#include "vec/core/field.h"
+
+namespace doris::vectorized {
+
+TEST(function_array_element_test, element_at) {
+    std::string func_name = "element_at";
+    Array empty_arr;
+
+    // element_at(Array<Int32>, Int32)
+    {
+        InputTypeSet input_types = {TypeIndex::Array, TypeIndex::Int32, TypeIndex::Int32};
+
+        Array vec = {Int32(1), Int32(2), Int32(3)};
+        DataSet data_set = {
+                {{vec, 0}, Null()},    {{vec, 1}, Int32(1)},     {{vec, 4}, Null()},
+                {{vec, -1}, Int32(3)}, {{vec, -3}, Int32(1)},    {{vec, -4}, Null()},
+                {{Null(), 1}, Null()}, {{empty_arr, 0}, Null()}, {{empty_arr, 1}, Null()}};
+
+        check_function<DataTypeInt32, true>(func_name, input_types, data_set);
+    }
+
+    // element_at(Array<Int8>, Int32)
+    {
+        InputTypeSet input_types = {TypeIndex::Array, TypeIndex::Int8, TypeIndex::Int32};
+
+        Array vec = {Int8(1), Int8(2), Int8(3)};
+        DataSet data_set = {
+                {{vec, 0}, Null()},    {{vec, 1}, Int8(1)},      {{vec, 4}, Null()},
+                {{vec, -1}, Int8(3)},  {{vec, -3}, Int8(1)},     {{vec, -4}, Null()},
+                {{Null(), 1}, Null()}, {{empty_arr, 0}, Null()}, {{empty_arr, 1}, Null()}};
+
+        check_function<DataTypeInt8, true>(func_name, input_types, data_set);
+    }
+
+    // element_at(Array<String>, Int32)
+    {
+        InputTypeSet input_types = {TypeIndex::Array, TypeIndex::String, TypeIndex::Int32};
+
+        Array vec = {Field("abc", 3), Field("", 0), Field("def", 3)};
+        DataSet data_set = {{{vec, 1}, std::string("abc")},
+                            {{vec, 2}, std::string("")},
+                            {{vec, 10}, Null()},
+                            {{vec, -2}, std::string("")},
+                            {{vec, 0}, Null()},
+                            {{vec, -10}, Null()},
+                            {{Null(), 1}, Null()},
+                            {{empty_arr, 0}, Null()},
+                            {{empty_arr, 1}, Null()}};
+
+        check_function<DataTypeString, true>(func_name, input_types, data_set);
+    }
+}
+
+} // namespace doris::vectorized
+
+int main(int argc, char** argv) {
+    ::testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}