Simplify new plan creation in the SDK

[eruizgar91]

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

Currently is a bit complex for a developer create a simple subscription, because the user has to create an assetPrice that pick the fee and other data.

Describe the solution you'd like

We could simplify this process for the final user, so they only need to pass the price that the want to set up and the token address.

      const assetRewardsMap = new Map([[address, BigInt(asset.price)]])

      const feeReceiver = await nvmApp.sdk.keeper.nvmConfig.getFeeReceiver()
      const assetPrice = new AssetPrice(assetRewardsMap).adjustToIncludeNetworkFees(
        feeReceiver,
        NETWORK_FEE_DENOMINATOR,
      )
      assetPrice.setTokenAddress(asset.token.address)

This code can be executed directly in the sdk, so the final user don't need to know how is happening internally.