Share options in the voting page

[jpaulet]

As voter I want to have a easy way to share the voting process to others.

Add a new "Share" button in the public voting page, that allows the voter to:

• [x] Add a share button (top-right area, in the same row of "Schedule" but floating in the right):

When clicked, a modal appear:

With the following share options:

• [x] Share with Telegram
• [x] Share with Whatsapp
• [x] Share on Twitter
• [x] Share on Facebook
• [x] Share via Mail
• [x] Copy URL component

Make sure to share ONLY the URL part without the # if present (to prevent sharing the PK if we use the auth with PK in the URL).

[selankon]

We can use https://www.npmjs.com/package/react-share

[selankon]

It actually exists a "share" component when voted, we should just adapt this

https://github.com/vocdoni/ui-scaffold/blob/78edc9847e53bc94556fb9fa0222cf2fdd321dc4/src/components/Process/View.tsx#L158