[FR] - Change representation of cost models in the code to JSON string

**Internal/External**
*Internal*

**Area**
*Other* Any other topic (Delegation, Ranking, ...).

**Describe the feature you'd like**
Currently cost models are represented [as an array with hard to understand values](https://github.com/IntersectMBO/cardano-api/blob/0eacd1f83ee20f19072a4b8d2a5d7cd27c0f088b/cardano-api/internal/Cardano/Api/Genesis.hs#L243). To make maintenance easier, they should be stored as JSON string in haskell (quasiquoted preferably). The cost model should be also linked to the original location in plutus repository in the code comment: https://github.com/IntersectMBO/plutus/blob/master/plutus-core/cost-model/data/builtinCostModel.json

A validation logic implemented in `cardano-testnet` would be nice to have: https://github.com/IntersectMBO/cardano-node/blob/cd3c037fa6d2f836794012f806cd32edfcf31763/cardano-testnet/src/Testnet/Defaults.hs#L88

**Describe alternatives you've considered**
n/a

**Additional context / screenshots**
n/a