[Enhancement] - Invite a Friend

[islandbitcoin]

Add a button that allows users to "invite a friend".

• press "invite a friend"
• enter email address or phone number
• press send
• Invitee will get an email and/or WhatsApp message and/or SMS inviting them to Flash.

Optional:

• invite tracking system (needs backend PR)
• incentive system for inviting friends (needs btcpayserver)

[Nodirbek75]

Create an backend issue to send email or sms to users @brh28

[Nodirbek75]

https://discord.com/channels/1201533062685663345/1211764905921875989/1394691083811946508

[Nodirbek75]

Add a section under community on the settings screen that navigates to the invite friends flow