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/e2e/ui/control-points.cy.js

@@ -9,7 +9,7 @@ describe('UI - Control Points', function () {
 
   it('Editor - No parameters: Drag control point of arc path', () => {
     const randomOffset = () => 2 + Math.round(10 + Math.random() * 40)
-    cy.get('#tool_source').click()
+    cy.get('#tool_source').click({ force: true })
     cy.get('#svg_source_textarea')
       .type('{selectall}', { force: true })
       .type(`<svg width="640" height="480" xmlns="http://www.w3.org/2000/svg">