Add icons for markets

[JonRay15]

Story

As a user I want to be able to see nice icons in Console for markets and assets So that I think "wow ... Console looks cool"

Acceptance Criteria

• [ ] Show in market header for current market
• [ ] Show in the market selector
• [x] Show in the markets page

Tasks

• [ ] UX (if needed)
• [ ] Design (if needed)
• [ ] Team and stakeholder review
• [ ] Specs reviewed and created or adjusted
• [ ] Implementation
• [ ] Testing (unit and/or e2e)
• [ ] Code review
• [ ] QA review

Sketch

Additional details / background info

[mattrussell36]

Parking this until https://github.com/vegaprotocol/frontend-monorepo/pull/5015 is merged as it contains asset icons