Fix kredits balance handling

Kredits are stored on the Token contract as uint256 / bignumbers with 18
decimal points. Just like Ether and required by the ERC20 standard.
So we need to work with bignumbers and format a bignumber value here.

app/utils/format-kredits.js

@@ -0,0 +1,9 @@
+import ethers from 'npm:ethers';
+
+export default function(value, options = {}) {
+  let etherValue = ethers.utils.formatEther(value);
+  if (!options.decimals) {
+    etherValue = parseInt(etherValue).toString();
+  }
+  return etherValue;
+}