share from email

[tttp]

the thank you emails often contain a request for the supporter to share the campaign.

right now, the message is simply redirecting to the page embedding the widget, but skip the main action and go directly to the share step.

the aim is to simplify that workflow so there are dedicated buttons in the email:

• share on twitter
• share on facebook
• share on X (whatsapp?)

as for the share step:

• share on facebook only needs the url of the page embedding the widget (potential problem, the widget might be embedded in multiple pages)
• share on twitter needs the url + a prefilled message
• share on whatsapp needs the url + a prefilled message

for both twitter and whatsapp, it might be possible to have more than a single message and randomly select one, as for the normal share step.

implementation:
have a mode on the widget that:

• do not display the step/widget
• emulate a click on the share button and redirect to either twitter/whatsapp/fb
• do count the share as an action (may be with a different type than share_click, eg share_email?)