fix(katana-core): crate can't be build without any feature

[kariy]

Currently, compiling katana-core will fail if the messaging feature is not enabled because we're using the ethers outside of the feature's scope. We would want to allow using katana-core as is without any features enabled. This issue means that downstream crates that rely on katana-core would have to enable this feature even if they don't need it.

Use the primitive-types where the U256 is being exported from, instead of relying on ethers, for usage outside of the messaging feature scope.

[codecov]

Codecov Report

Attention: 618 lines in your changes are missing coverage. Please review.

Comparison is base (374f2bf) 70.06% compared to head (70dc1de) 70.59%.
Report is 30 commits behind head on main.

Files	Patch %	Lines
bin/katana/src/main.rs	0.00%	94 Missing ⚠️
crates/katana/runner/src/logs.rs	10.00%	72 Missing ⚠️
bin/saya/src/main.rs	0.00%	56 Missing ⚠️
crates/saya/core/src/lib.rs	0.00%	50 Missing ⚠️
crates/katana/primitives/src/genesis/mod.rs	92.40%	35 Missing ⚠️
bin/saya/src/args/mod.rs	0.00%	33 Missing ⚠️
...es/saya/core/src/data_availability/celestia/mod.rs	0.00%	33 Missing ⚠️
crates/katana/runner/src/prefunded.rs	0.00%	31 Missing ⚠️
bin/saya/src/args/data_availability.rs	0.00%	24 Missing ⚠️
bin/sozo/src/ops/migration/mod.rs	30.30%	23 Missing ⚠️
... and 28 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1527      +/-   ##
==========================================
+ Coverage   70.06%   70.59%   +0.53%     
==========================================
  Files         236      257      +21     
  Lines       22531    24975    +2444     
==========================================
+ Hits        15786    17632    +1846     
- Misses       6745     7343     +598     

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