1. remove FE config `enable_array_type`
2. limit the nested depth of array in FE side.
3. Fix bug that when loading array from parquet, the decimal type is treated as bigint
4. Fix loading array from csv(vec-engine), handle null and "null"
5. Change the csv array loading behavior, if the array string format is invalid in csv, it will be converted to null.
6. Remove `check_array_format()`, because it's logic is wrong and meaningless
7. Add stream load csv test cases and more parquet broker load tests
Doris do not support explicitly cast NULL_TYPE to ANY type .
```
mysql> select cast(NULL as int);
ERROR 1105 (HY000): errCode = 2, detailMessage = Invalid type cast of NULL from NULL_TYPE to INT
```
So we should also forbid user from casting NULL_TYPE to ARRAY type.
This commit will produce the following effect:
```
mysql> select cast(NULL as array<int>);
ERROR 1105 (HY000): errCode = 2, detailMessage = Invalid type cast of NULL from NULL_TYPE to ARRAY<INT(11)>
```
actual result
select cast("0.0000031417" as date);
+------------------------------+
| CAST('0.0000031417' AS DATE) |
+------------------------------+
| 2000-00-00 |
+------------------------------+
expect result
select cast("0.0000031417" as date);
+------------------------------+
| CAST('0.0000031417' AS DATE) |
+------------------------------+
| NULL |
+------------------------------+
