Adjust deps to current usage

depcheck is useful here. Has some false reports, but there are some
unused packages and some missing ones. Also I moved types to dev-
dependencies because we don't use them at runtime.

package.json

@@ -17,8 +17,7 @@
     "@mui/icons-material": "^5.0.3",
     "@mui/material": "^5.0.3",
     "@mui/styles": "^5.0.1",
-    "@types/bcrypt": "^5.0.0",
-    "@types/bcryptjs": "^2.4.2",
+    "@mui/system": "^5.0.3",
     "acorn": "^8.4.1",
     "acorn-walk": "^8.1.1",
     "arg": "^5.0.0",
@@ -26,10 +25,8 @@
     "better-react-mathjax": "^1.0.3",
     "clsx": "^1.1.1",
     "date-fns": "^2.25.0",
-    "electron-config": "^2.0.0",
     "escodegen": "^1.11.0",
     "file-saver": "^1.3.8",
-    "fs": "^0.0.1-security",
     "jquery": "^3.5.0",
     "js-sha256": "^0.9.0",
     "jszip": "^3.7.0",
@@ -57,6 +54,7 @@
     "@pmmmwh/react-refresh-webpack-plugin": "^0.5.1",
     "@testing-library/cypress": "^8.0.1",
     "@types/acorn": "^4.0.6",
+    "@types/bcryptjs": "^2.4.2",
     "@types/escodegen": "^0.0.7",
     "@types/file-saver": "^2.0.3",
     "@types/lodash": "^4.14.168",
@@ -90,7 +88,6 @@
     "typescript": "^4.2.4",
     "webpack": "^4.46.0",
     "webpack-cli": "^3.3.12",
-    "webpack-dev-middleware": "^3.7.3",
     "webpack-dev-server": "^3.11.2"
   },
   "engines": {