[BugFix](JDBC Catalog) fix jdbc catalog query bitmap may cause be cor…

…e sometimes (apache#26933)

BitmapValue::write_to will get a string with size 1 for empty BitmapValue, however the size 1 string will reinterpret to BitmapValue* back in ColumnComplexType::insert:
void insert(const Field& x) override {
const String& s = doris::vectorized::get<const String&>(x);
data.push_back(reinterpret_cast<const T>(s.c_str()));
}

in data.push_back will goto BitmapValue copy constructor, as the _type is not first member in BitmapValue, cause access to an unknown memory location.

be/src/util/bitmap_value.h

@@ -1259,10 +1259,9 @@ class BitmapValue {
     }
 
     static std::string empty_bitmap() {
-        static BitmapValue bitmap;
-        std::string buf;
-        buf.resize(bitmap.getSizeInBytes());
-        bitmap.write_to(buf.data());
+        std::string buf(sizeof(BitmapValue), 0);
+        BitmapValue* bitmap_value = reinterpret_cast<BitmapValue*>(buf.data());
+        bitmap_value->_type = EMPTY;
         return buf;
     }