Set handlers use unified jsonPrint with prettifier if needed

test/cmdlineTests/combined_json_with_devdoc/args

@@ -0,0 +1 @@
+--combined-json devdoc --pretty-json --allow-paths .

test/cmdlineTests/combined_json_with_devdoc/input.sol

@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0;
+
+/// @dev This is devdoc.
+contract C {}
+
+/// And this is a notice.
+contract D {}

test/cmdlineTests/combined_json_with_devdoc/output

@@ -0,0 +1,25 @@
+{
+  "contracts":
+  {
+    "combined_json_with_devdoc/input.sol:C":
+    {
+      "devdoc":
+      {
+        "details": "This is devdoc.",
+        "kind": "dev",
+        "methods": {},
+        "version": 1
+      }
+    },
+    "combined_json_with_devdoc/input.sol:D":
+    {
+      "devdoc":
+      {
+        "kind": "dev",
+        "methods": {},
+        "version": 1
+      }
+    }
+  },
+  "version": "<VERSION REMOVED>"
+}