Refactor enumerableMap generate and tests (#4760)

scripts/generate/templates/EnumerableMap.opts.js

@@ -0,0 +1,18 @@
+const mapType = str => (str == 'uint256' ? 'Uint' : `${str.charAt(0).toUpperCase()}${str.slice(1)}`);
+const formatType = (keyType, valueType) => ({
+  name: `${mapType(keyType)}To${mapType(valueType)}Map`,
+  keyType,
+  valueType,
+});
+
+const TYPES = [
+  ['uint256', 'uint256'],
+  ['uint256', 'address'],
+  ['address', 'uint256'],
+  ['bytes32', 'uint256'],
+].map(args => formatType(...args));
+
+module.exports = {
+  TYPES,
+  formatType,
+};