Upgrade Maven builds to Node.js v16 and npm v8 (#1353)

For Main UI & Basic UI, with appropriate changes for the latter.
Leaving HABot to current versions for now until the build is fixed.

Signed-off-by: Jan N. Klug <[email protected]>

Author: J-N-K

.gitignore

@@ -10,3 +10,4 @@ bin/
 features/*/src/main/history
 npm-debug.log
 node_modules/
+.idea

README.md

@@ -57,7 +57,8 @@ You find the following repository structure:
 
 In most cases, you **don't** need a Java development environment for UI development.
 
-Instead, make sure you have NodeJS 12.16 or later and npm 6.14 or later installed.
+Instead, make sure you have NodeJS 16.14 (HABot: 12.16) or later and npm 8.6 (HABot: 6.14) or later installed.
+
 
 Then identify in the `bundles` directories where the frontend code is - for instance, for the main UI it is `bundles/org.openhab.ui/web/`.
 Then follow the instructions in the specific add-on's `CONTRIBUTING.md` file to get started. In the main UI's case, it is located in [bundles/org.openhab.ui/CONTRIBUTING.md](https://github.com/openhab/openhab-webui/blob/master/bundles/org.openhab.ui/CONTRIBUTING.md). In many cases it will involve executing some `npm` commands to install dependencies and start a development server.

bundles/org.openhab.ui.basic/gulpfile.js

@@ -3,7 +3,7 @@
 
 	var
 		gulp = require("gulp"),
-		sass = require("gulp-sass"),
+		sass = require('gulp-sass')(require('node-sass')),
 		uglify = require("gulp-uglify"),
 		eslint = require("gulp-eslint");