Make ERC20Votes independent from ERC20Permit (#3816)

Co-authored-by: Francisco <frangio.1@gmail.com>

scripts/generate/templates/Checkpoints.js

@@ -107,6 +107,13 @@ function getAtProbablyRecentBlock(${opts.historyTypeName} storage self, uint256
     return pos == 0 ? 0 : _unsafeAccess(self.${opts.checkpointFieldName}, pos - 1).${opts.valueFieldName};
 }
 
+/**
+ * @dev Returns checkpoint at given position.
+ */
+function getAtPosition(History storage self, uint32 pos) internal view returns (Checkpoint memory) {
+    return self._checkpoints[pos];
+}
+
 /**
  * @dev Pushes a value onto a History so that it is stored as the checkpoint for the current block.
  *