Add split method for uint

**Is your feature request related to a problem? Please describe.**

In situations like:
- https://github.com/kkrt-labs/kakarot-rpc/blob/e09b452b258d6ef1f6f12c44d856f178cfa870a3/src/eth_provider/utils.rs#L45-L51
- https://github.com/dojoengine/dojo/blob/f0637f928470217fccd60fe15b1b9c6fefd5c984/crates/katana/primitives/src/utils/mod.rs#L11-L15

it is useful to have a method that splits a uint but this method is not yet available in the implementation.

**Describe the solution you'd like**

It would therefore be appropriate to implement a method that splits a uint into two equal parts with high and low, based on the model of what is done here

https://github.com/recmo/uint/blob/41c45f89e6dab00bdb2878bf7495c5df864b8784/src/algorithms/mod.rs#L37-L39

This would allow for example to split a U256 into a high part and a low part.