Merge branch '2020.06-rc' into stable

diff --cc composer.lock
index 155f754ae0d87ad3e07a98d32ab885061649989f,583a0f46fb6f4cc17fb31f39b573055879f04e87..45c6137a4fe62b8344e10577935915706d6f3b8e
--- 1/composer.lock
--- 2/composer.lock
+++ b/composer.lock
@@@ -1721,14 -1732,14 +1732,72 @@@
                  "time",
                  "validate"
              ],
-             "time": "2019-01-21T21:10:34+00:00"
+             "time": "2020-05-20T06:46:22+00:00"
+         },
+         {
+             "name": "npm-asset/perfect-scrollbar",
+             "version": "0.6.16",
+             "dist": {
+                 "type": "tar",
+                 "url": "https://registry.npmjs.org/perfect-scrollbar/-/perfect-scrollbar-0.6.16.tgz",
++                "shasum": "b1d61a5245cf3962bb9a8407a3fc669d923212fc"
++            },
++            "type": "npm-asset-library",
++            "extra": {
++                "npm-asset-bugs": {
++                    "url": "https://github.com/noraesae/perfect-scrollbar/issues"
++                },
++                "npm-asset-files": [
++                    "dist",
++                    "src",
++                    "index.js",
++                    "jquery.js",
++                    "perfect-scrollbar.d.ts"
++                ],
++                "npm-asset-main": "./index.js",
++                "npm-asset-directories": [],
++                "npm-asset-repository": {
++                    "type": "git",
++                    "url": "git+https://github.com/noraesae/perfect-scrollbar.git"
++                },
++                "npm-asset-scripts": {
++                    "test": "gulp",
++                    "before-deploy": "gulp && gulp compress",
++                    "release": "rm -rf dist && gulp && npm publish"
++                },
++                "npm-asset-engines": {
++                    "node": ">= 0.12.0"
++                }
++            },
++            "license": [
++                "MIT"
++            ],
++            "authors": [
++                {
++                    "name": "Hyunje Jun",
++                    "email": "me@noraesae.net"
++                },
++                {
++                    "name": "Hyunje Jun",
++                    "email": "me@noraesae.net"
++                }
++            ],
++            "description": "Minimalistic but perfect custom scrollbar plugin",
++            "homepage": "https://github.com/noraesae/perfect-scrollbar#readme",
++            "keywords": [
++                "frontend",
++                "jquery-plugin",
++                "scroll",
++                "scrollbar"
++            ],
++            "time": "2017-01-10T01:03:05+00:00"
 +        },
 +        {
 +            "name": "npm-asset/perfect-scrollbar",
 +            "version": "0.6.16",
 +            "dist": {
 +                "type": "tar",
 +                "url": "https://registry.npmjs.org/perfect-scrollbar/-/perfect-scrollbar-0.6.16.tgz",
                  "shasum": "b1d61a5245cf3962bb9a8407a3fc669d923212fc"
              },
              "type": "npm-asset-library",