npm build cleanup

[Andreas-Huber]

The build was not very intuitive on unix, because it required different commands per operation system

Done:

• Removed Node-red dependency
• npm update
• Made the build script OS independent with run-script-os
• Tested the build with a temporary matrix build strategy on Win, Linux, and macOS with node 10, 12, and 14 (the active LTS releases) and node 15 manually.

ToDo List:

• One build for Linux mac and windows. npm run build ✅
  • Test under Linux ✅
  • Test under Windows ✅
  • Test under MacOS ✅
• remove the requirement for global eslint install ✅
• remove the requirement for global tsc install ✅ (Actually it was just my mistake, there was never a requirement to install eslint and tsc globally if you just run it from npm. If you want to run it from the shell you have to install it globally or use the assembly form ./node_modules/.bin/{tsc/eslint}. Npm does that automatically)
• Get rid of the bcrypt warnings and the g++ requirement ✅
• Evaluate whether node-red is a dependency or not ✅ No it is not.
• Create contribution guideline: ✅
  • Document dependencies on rsync/robocopy & powershell & docker ✅
  • Development guide ✅
  • document create-node ✅
• npm script for _createNode.ps1 ✅
• remove matrix build strategy? ✅ Removed, because unnecessary as discussed.
• Set Bavaria Black dependency to update all minor versions ✅
• Upcoming changes ✅

Resolves #72

[Andreas-Huber]

@Dirnei now it's ready to review. Converted it back to draft yesterday because I forgot as always to fill the upcoming changelog.