Backend/FiatValueEstimation: fix CoinCap querying

Via the /rates API, ETC was not available, but via /assets it
is, which mitigates [1].

[1] #204

src/GWallet.Backend/FiatValueEstimation.fs

@@ -14,12 +14,19 @@ module FiatValueEstimation =
     {
       "data": {
         "id": "bitcoin",
+        "rank": "1",
         "symbol": "BTC",
-        "currencySymbol": "x",
-        "type": "crypto",
-        "rateUsd": "6444.3132749056076909"
+        "name": "Bitcoin",
+        "supply": "19281750.0000000000000000",
+        "maxSupply": "21000000.0000000000000000",
+        "marketCapUsd": "450487811256.3001791347094000",
+        "volumeUsd24Hr": "6522579119.6754297896356342",
+        "priceUsd": "23363.4297331051475688",
+        "changePercent24Hr": "-0.0049558876182867",
+        "vwap24Hr": "23430.6497382042627725",
+        "explorer": "https://blockchain.info/"
       },
-      "timestamp": 1536347871542
+      "timestamp": 1675571191130
     }
     """>
 
@@ -44,7 +51,7 @@ module FiatValueEstimation =
             let baseUrl =
                 match provider with
                 | PriceProvider.CoinCap ->
-                    SPrintF1 "https://api.coincap.io/v2/rates/%s" tickerName
+                    SPrintF1 "https://api.coincap.io/v2/assets/%s" tickerName
                 | PriceProvider.CoinGecko ->
                     SPrintF1 "https://api.coingecko.com/api/v3/simple/price?ids=%s&vs_currencies=usd" tickerName
             let uri = Uri baseUrl
@@ -66,14 +73,10 @@ module FiatValueEstimation =
         | Some (_, json) ->
             try
                 let tickerObj = CoinCapProvider.Parse json
-                return Some tickerObj.Data.RateUsd
+                return Some tickerObj.Data.PriceUsd
             with
             | ex ->
-                if currency = ETC then
-                    // interestingly this can throw in CoinCap because retreiving ethereum-classic doesn't work...
-                    return None
-                else
-                    return raise <| FSharpUtil.ReRaise ex
+                return raise (Exception(SPrintF2 "Could not parse CoinCap's JSON (for %A): %s" currency json, ex))
     }
 
     let private QueryCoinGecko currency = async {
@@ -98,9 +101,6 @@ module FiatValueEstimation =
         let coinCapJob = QueryCoinCap currency
         let bothJobs = FSharpUtil.AsyncExtensions.MixedParallel2 coinGeckoJob coinCapJob
         let! maybeUsdPriceFromCoinGecko, maybeUsdPriceFromCoinCap = bothJobs
-        if maybeUsdPriceFromCoinCap.IsSome && currency = Currency.ETC then
-            Infrastructure.ReportWarningMessage "Currency ETC can now be queried from CoinCap provider?"
-            |> ignore<bool>
         let result =
             match maybeUsdPriceFromCoinGecko, maybeUsdPriceFromCoinCap with
             | None, None -> None