Add scripts for running ghci and ghcid

ghci needs some convincing to work with a custom prelude. Therefore,
we cannot use `stack ghci`.

load-all.ghci

+:set -isrc -XOverloadedStrings -XNamedFieldPuns -XLambdaCase -XMultiWayIf -XScopedTypeVariables
+
+:set -XNoImplicitPrelude
+:load src/Prelude.hs
+:set -XImplicitPrelude
+
+:load src/QBar/Cli.hs

run-ghci.sh

+#!/usr/bin/env bash
+set -e
+# see https://gitlab.haskell.org/ghc/ghc/-/issues/10920
+stack exec -- ghci -ghci-script load-all.ghci

run-ghcid.sh

+#!/usr/bin/env bash
+set -e
+stack exec -- ghcid -c "ghci -ghci-script load-all.ghci"