update vue2 -> vue3, fixes #3747

.eslintrc.json

app/views/oer/mymaterial/edit.php

lib/classes/StudipController.php

lib/classes/forms/Form.php

package-lock.json

package.json

resources/assets/javascripts/bootstrap/avatar.js

resources/assets/javascripts/bootstrap/courseware.js

resources/assets/javascripts/bootstrap/forms.js

resources/assets/javascripts/bootstrap/mvv_difflog.js

resources/assets/javascripts/bootstrap/oer.js

resources/assets/javascripts/bootstrap/vue.js

resources/assets/javascripts/chunk-loader.js

resources/assets/javascripts/chunks/avatar.js

resources/assets/javascripts/chunks/vue.js

resources/assets/javascripts/jquery-bundle.js

resources/assets/javascripts/lib/admission.js

resources/assets/javascripts/lib/blubber.js

resources/assets/javascripts/lib/datetime.js

resources/assets/javascripts/lib/files.js