The default return value of u256 is inconsistent with Solidity

```fe
contract C {
state: u256

}
```
the return value of state is ""

```solidity
contract C {
uint public state;
}
```
the return value of state is "0000000000000000000000000000000000000000000000000000000000000000"

Reproduce the issue using the Fe contract snippet and compare its u256 state return value with the Solidity uint example. The work is done when the Fe result matches the expected 64-character zero value for the default state.

Written by the indexing model from the issue text.