Ability to reset yellow line position for Grid bot#420

The logic is weight grid lines “differently” based on new position of yellow line.

Currently grid bot will distribute each line “equally”, which means the average buy price aka yellow line will be placed at the middle.

If we are able to reset the yellow line position, say 10% from bottom, bot will reduce the grid size at upside and tops in to downside to make grid lines weight higher, additional funds may required if not enough.

A side effect of this feature is bot will gain lower profit at far area from yellow line position due to weighted lower. But easy fix by reset the yellow line to 40-60% of the grid, by 50% will be same as now.

Similar to Add funds, bot will reset the grid with new weighted grid distribution based on specific yellow line position.

As for yellow line position, 10% from bottom is an example, users can slide between 10-90% from bottom to top. 90% from bottom means aggressive for bot to follow the trend, it generates more profit but risks of negative PNL as bot buys/sells more at expensive price.

This feature is designed for flexibility depends of grid coverage. It is another legit way to drag down the yellow line, making true positive PNL.

Also helps grid bot manages investment efficiency since most coins have mountain-like spike chart, means a few transactions done at upside compare to middle-bottom of the grid.