separate svgcanvas from svgedit

now you can use directlt svgcanvas. see readme.md

* configure workspaces
* move svgcanvas to packages folder
* move utils to common and paint to svgcanvas
* make svgcanvas a dependency of svgedit
* update deps
* workspaces requires npm 7 at least so the ci needs a new node version
* update github actions to V3
* update snapshots using custom svg exports
* remove unmaintained cypress snapshot plugin
* new github action to add coverage in PR
* Update onpushandpullrequest.yml
* svgcanvas v7.1.6

cypress.config.js

@@ -6,12 +6,6 @@ module.exports = defineConfig({
   pageLoadTimeout: 120000,
   includeShadowDom: true,
   scrollBehavior: false,
-  'cypress-plugin-snapshots': {
-    autoCleanUp: true,
-    prettier: true,
-    updateSnapshots: false,
-    diffLines: 5
-  },
   e2e: {
     // We've imported your old cypress plugins here.
     // You may want to clean this up later by importing these.