Vue update to v3

[ksy36]

I've updated vue and related packages and these are the changes:

• Replaced floating-vue with vue-popperjs
• Replaced vue-spinner with a custom spinner component
• Switched to h() and render() API instead of Vue.extend for programmatic component creation
• Removed filters
• Updated jest and fixed tests (copied some of the setup from https://github.com/MozillaSecurity/FuzzManager as it was migrated a while back)
• Updated eslint and changed config a bit
• Removed unused js and css bootstrap-vue and vuejs-slider.js
• Fixed warnings in the console

[jgraham]

Assuming that it works this seems good to go :)