Describe the bug

-- Original report --

link: https://alpha.try.decidim.org/assemblies/jessie/f/6/proposals/23

the buttons:

• edit proposal and withdraw has different size
• stop following is misaligned with the others

-- End of original report --

To Reproduce
Steps to reproduce the behavior:

1. Go to '(https://alpha.try.decidim.org/assemblies/jessie/f/6/proposals)'
2. Create a proposal
3. See buttons with different width

Expected behavior

• To have the buttons with the same width (the longest one)
• Each button must have its corresponding icon:
  • For "Edit proposal" use class "ri-pencil-line"
  • For "Withdraw proposal" use class "ri-arrow-go-back-line"
• Fix the behavior of the "Follow" button.

Screenshots

Extra data (please complete the following information):

• Device: Desktop
• Decidim Version: 0.28.0.dev
• Decidim installation: Alpha Try Decidim

Additional context
Add any other context about the problem here.