fix(examples): webpack css import fix, package.json cleanup, small chores

[zbynekstara]

• use sideEffects: true in webpack to enable css import inside javascript
• cleanup all package.json files - remove references to dagre, graphlib, jquery, lodash
• cleanup all .gitignore files - remove references to yarn
• provide "outDir": "./build" in all tsconfig.json files
• add explicit volta specification to all package.json files
• index.html harmonization across examples
• webpack rules harmonization across examples