Group-income-simple: Uniformize invitation link display across the app

[sandrina-p]

Problem

Recently @mmbotelho designed a better invitation link display with "click-to-copy" functionality. That was implemented only in the Invite Links table (#664).

We need to also implement it at:

• Modal "Add members" when the group has less than 3 members.
• Proposal widget when an invite member proposal is accepted.

Solution

• Implement the component in the missing places.
• Add a usage demo to the Design System

[sandrina-p]

@SebinSong, I wonder if you would like to pick up this issue. It would be a great way for you to practice your skills when it comes to create reusable components. If you want to, feel free to assign this issue to yourself.

[SebinSong]

@sandrina-p I would definitely love to work on this issue.