Create size slider

[JonRay15]

Story

As a user I want a order size slider So that I can size my order without manually typing out numbers

Acceptance Criteria

• [x] I can set the size I want on a slider (sketch is stolen from Binance, ignore, use the one we already used for leverage)
• [x] When I set my size on the slider the written size in the ticket updates on screen
• [x] If i set my size manually in written text the slider moves to reflect this
• [x] In isolated margin mode:
  • [x] When I have no open position the max size on the slider is the position size that would use up all my remaining general account as margin, eg. MAX = balance in general account / margin factor
  • [x] When I am making an existing position larger then same approach as above
  • [x] When I am flipping an existing position then the max is the amount needed to use all my balance on the other side, eg. MAX = (current margin that would be returned to you + balance in general account) / margin factor

Tasks

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

Sketch

Additional details / background info

Core PR for slippage removal: https://github.com/vegaprotocol/vega/issues/10754

[mattrussell36]

Can we get the formula for calculating the max size possible?

[JonRay15]

Moved the cross margin onto #5963