Ensure visual consistency across spinner components

Problem

Some of our In progress/loading states are still using default Bootstrap spinners v.s our current spinners listed in Pajamas. This issue is an attempt at tracking and listing them.

Proposal

  • Migrate Bootstrap spinners to Pajamas spinners.

Example

Issue sidebar when expanded.

image

List

  • Issue sidebar
    • Assignee
    • Milestone
    • Labels
  • Activity page
  • Milestones page. Use the dropdown for "select project to create a milestone"
  • Issue creation
    • Assignee
    • Milestone
    • Labels
  • Add any?