Feat: Add image generation

[Dominic-Marcelino]

Add the option to save the WiFi Card as a image and PDF. Important: This process needs be completely in the client. No WiFi data should be ever transferred to any server

🎨 Design-Idea:
Selectable Button for download next to print-button-

👨🏽‍💻 Development rfc:

• DOM to PDF / Image (mostly first to canvas, than to image):
  https://www.npmjs.com/package/html2canvas
• Apply Custom Style via onclone -- example
• For Pdf: jsPdf (also should work with html2canvas)

share-wifi-cool/src/components/WiFiCard.vue

Line 54 in 5865c71

<v-button disabled textStyle class="mr-3">