CCIPReader pricing tests (#15264)

* Add Test_GetChainFeePriceUpdates (#15240)

Add Test_GetChainFeePriceUpdates

* Bind real contracts per chain in CCIPReader test (#15282)

Add functionality to bind more contracts to different chains (using same simulated backend for simplicity) in ccipreader tester.

LinkPriceUSD test
GetMedianDataAvailabilityGasConfig

* Test_GetWrappedNativeTokenPriceUSD (#15316)

Test_GetWrappedNativeTokenPriceUSD

* comments