[Bug]: Discrepancy of extended Token with legacy library

### Preflight Checklist

- [x] I have read the [Contributing Guidelines](https://github.com/EnAccess/OpenPAYGO-python/blob/main/CONTRIBUTING.md) for this project, if it exists.
- [x] I agree to follow the [Code of Conduct](https://github.com/EnAccess/OpenPAYGO-python/blob/main/CODE_OF_CONDUCT.md) that this project adheres to.
- [x] I have searched the [issue tracker](https://github.com/EnAccess/OpenPAYGO-python/issues) for a feature request that matches the one I want to file, without success.

### Expected Behavior

Legacy and new library should generate the same extended tokens.

### Actual Behavior

When generating extended tokens there is a difference for `ADD_TIME` tokens.

**New lib:**

```python
# OpenPAYGO-python
from openpaygo import OpenPAYGOTokenEncoder, TokenType

encoder = OpenPAYGOTokenEncoder()

new_count, final_token = encoder.generate_token(
secret_key="bc41ec9530f6dac86b1a29ab82edc5fb",
count=2,
value=1,
token_type=TokenType.ADD_TIME,
starting_code=516959010,
restricted_digit_set=False,
extended_token=True,
)

print(f"{new_count=}")
print(f"{final_token=}")
```

yields

```sh
new_count=4
final_token='584694959011'
```

**Legacy:**

```python
# OpenPAYGO Token
import codecs
from importlib import import_module

openpaygo_token = import_module("openpaygo-token")
encoder = openpaygo_token.OPAYGOEncoder()
shared = openpaygo_token.OPAYGOShared

new_count, final_token = encoder.generate_extended_token(
key=codecs.decode("bc41ec9530f6dac86b1a29ab82edc5fb", "hex"),
count=2,
value=1,
# mode=shared.TOKEN_TYPE_ADD_TIME,
starting_code=516959010,
restricted_digit_set=False,
)

print(f"{new_count=}")
print(f"{final_token=}")
```

```sh
new_count=3
final_token='660362959011'
```

### Steps to reproduce

Run the code from above.

This might be related to the legacy being hardcoded to `SET_TIME` for extended mode. Is the expected behaviour?

### What operating system(s) are you using?

macOS

### Additional Information

_No response_