Merge #691

691: display call stack for unsuccessful unsafe calls r=piotr-iohk a=KtorZ

# Issue Number

<!-- Put here a reference to the issue this PR relates to and which requirements it tackles -->


# Overview

<!-- Detail in a few bullet points the work accomplished in this PR -->

- [x] I have added "stack traces" for unsafe calls when they fail.

# Comments

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It's not much, but it turns:

```
       uncaught exception: ErrorCall
       TextDecodingError {getTextDecodingError = "Unable to decode Address: encoding is neither Bech32 nor Base58."}
       CallStack (from HasCallStack):
         error, called at src/Cardano/Wallet/Unsafe.hs:56:13 in cardano-wallet-core-2019.7.24-vtyOM1MPP4BB3M0K9gXCg:Cardano.Wallet.Unsafe
```


into

```
       uncaught exception: ErrorCall
       TextDecodingError {getTextDecodingError = "Unable to decode Address: encoding is neither Bech32 nor Base58."}
       CallStack (from HasCallStack):
         error, called at src/Cardano/Wallet/Unsafe.hs:58:13 in cardano-wallet-core-2019.7.24-vtyOM1MPP4BB3M0K9gXCg:Cardano.Wallet.Unsafe
         unsafeDecodeAddress, called at test/unit/Cardano/Wallet/Jormungandr/CompatibilitySpec.hs:121:21 in main:Cardano.Wallet.Jormungandr.CompatibilitySpec
```

which makes it easier to locate the point of failure.

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Co-authored-by: KtorZ <matthias.benkort@gmail.com>

lib/core/src/Cardano/Wallet/Unsafe.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE ScopedTypeVariables #-}
@@ -38,6 +39,8 @@ import Data.Proxy
     ( Proxy )
 import Data.Text
     ( Text )
+import GHC.Stack
+    ( HasCallStack )
 
 import qualified Cardano.Crypto.Wallet as CC
 import qualified Codec.CBOR.Decoding as CBOR
@@ -46,29 +49,30 @@ import qualified Data.ByteString.Lazy as BL
 
 
 -- | Decode an hex-encoded 'ByteString' into raw bytes, or fail.
-unsafeFromHex :: ByteString -> ByteString
+unsafeFromHex :: HasCallStack => ByteString -> ByteString
 unsafeFromHex =
     either (error . show) id . convertFromBase @ByteString @ByteString Base16
 
 -- | Decode a bech32-encoded 'Text' into an 'Address', or fail.
-unsafeDecodeAddress :: DecodeAddress t => Proxy t -> Text -> Address
+unsafeDecodeAddress :: (HasCallStack, DecodeAddress t) => Proxy t -> Text -> Address
 unsafeDecodeAddress proxy =
     either (error . show ) id . decodeAddress proxy
 
 -- | Run a decoder on a hex-encoded 'ByteString', or fail.
-unsafeDecodeHex :: Get a -> ByteString -> a
+unsafeDecodeHex :: HasCallStack => Get a -> ByteString -> a
 unsafeDecodeHex get = runGet get . BL.fromStrict . unsafeFromHex
 
 -- | Build a 'XPrv' from an hex-encoded bytestring
-unsafeXPrv :: ByteString -> XPrv
+unsafeXPrv :: HasCallStack => ByteString -> XPrv
 unsafeXPrv hex =
     case convertFromBase @_ @ByteString Base16 hex >>= CC.xprv of
         Left e -> error $ "unsafeXPrv: " <> e
         Right a -> a
 
 -- | Build 'Mnemonic' from literals
 unsafeMkMnemonic
-    :: forall mw n csz. (ConsistentEntropy n mw csz, EntropySize mw ~ n)
+    :: forall mw n csz
+    .  (ConsistentEntropy n mw csz, EntropySize mw ~ n, HasCallStack)
     => [Text]
     -> Mnemonic mw
 unsafeMkMnemonic m =
@@ -88,7 +92,8 @@ unsafeRunExceptT = runExceptT >=> \case
 
 -- | CBOR deserialise without error handling - handy for prototypes or testing.
 unsafeDeserialiseCbor
-    :: (forall s. CBOR.Decoder s a)
+    :: HasCallStack
+    => (forall s. CBOR.Decoder s a)
     -> BL.ByteString
     -> a
 unsafeDeserialiseCbor decoder bytes = either