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/support/ui-test-helper.js

@@ -1,11 +1,6 @@
-export const approveStorage = () => {
-  cy.get('#storage_ok').click()
-}
-
 export const visitAndApproveStorage = () => {
-  cy.viewport(512, 512)
   cy.visit('/instrumented/editor/index.html')
-  approveStorage()
+  cy.get('#storage_ok').click()
 }
 
 export const openMainMenu = () => {
@@ -22,11 +17,3 @@ export const selectEnglish = () => {
   cy.get('#lang_select').select('en')
   cy.get('#tool_prefs_save').click()
 }
-
-export const testSnapshot = () => {
-  cy.window().then((win) => { // access to the remote Window so we can get the svgEditor variable
-    const svgString = win.svgEditor.svgCanvas.getSvgString()
-    const svgDom = new DOMParser().parseFromString(svgString, 'text/html').querySelector('body')
-    cy.wrap(svgDom).toMatchSnapshot()
-  })
-}