Add uniqueness check to "Create project" command (#5100)

* Add failing playwright test

* Make create generate a unique name if the given one collides

* Add a new consolidated getUniqueProjectName function with tests

* Use getUniqueProjectName

* Replace "New project" button text with "Create project"
cc @pierremtb

* Extend the e2e test to show the incrementing behavior
cc @lf94

e2e/playwright/fixtures/toolbarFixture.ts

@@ -63,6 +63,10 @@ export class ToolbarFixture {
     this.exeIndicator = page.getByTestId('model-state-indicator-execution-done')
   }
 
+  get logoLink() {
+    return this.page.getByTestId('app-logo')
+  }
+
   startSketchPlaneSelection = async () =>
     doAndWaitForImageDiff(this.page, () => this.startSketchBtn.click(), 500)