fix: assert custom asset price is less than the price cap

[mpsc0x]

The oracle module allows either the asset listing admin or the pool admin to set a custom price for certain assets. However, the set_asset_custom_price function does not verify whether a price cap is defined for the asset. As a result, if a custom price is set above the cap, the oracle will still return the capped price rather than the custom price. This discrepancy can lead to unintended consequences, as the effective price used by the system will differ from the custom price that was set. The PR corrects this behaviour.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.09%. Comparing base (886d7d9) to head (05365e3).
⚠️ Report is 5 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #45      +/-   ##
==========================================
+ Coverage   96.89%   97.09%   +0.19%     
==========================================
  Files          16       16              
  Lines         515      516       +1     
==========================================
+ Hits          499      501       +2     
+ Misses         16       15       -1     

Flag	Coverage Δ
move	97.09% <ø> (+0.19%)	⬆️

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