Simplify Margin Position window

The last discussion on this topic wasn't successful, but I got some negative feedback from other users and I don't like the actual layout/behavior either, therefore we should change the things.

- Move the MARKET column on the second position and put it on the same place as it is on the Open Orders window
- Make the column BALANCE till TOTAL (BTS) clickable to adjust margin position and use a different background for :hover to make the feature visible
- Make the column CALL PRICE till UNITS also clickable/visible to inverse units
- Remove the picker on UNITS column for inverse/market, because we already have a column with MARKET, no need to double click for one action


Start by locating the Margin Position window and the Open Orders window, then compare their column layouts and interactions. Implement the requested column ordering, hover and click behavior, and removal of the UNITS picker; done means each listed interaction is visible and matches the stated behavior.

Written by the indexing model from the issue text.