DM-5763: XYPlot decimation options

[tgoldina]

• Added decimation options to XYPlot options panel when numpoints exceed decimation limit of 5000
• Changed selected series to be on top of data series to speed up selection change in Firefox
• Added legend to decimated plot
• Updated syncCharts saga to ignore sort action when refetching table statistics and histogram data

[loitly]

• clicking ‘ok’ on the options should show validation errors on required fields, i.e. X, Y. instead of doing nothing.
• just an idea.. when it’s decimated, you cannot ‘select’ multiple points. Yet, there is no indication that is normal. so, instead of show/hide the icons, gray it out when it’s not applicable. and in the decimation case, you can specifically say that it’s not supported.
• some code is modifying the table’s results after filtering. i’ve seen this when tbl_id is not removed from request when doing a new search. may not be xyplot problem. could be image.
• xyPlot selected points is off. i plot ra/dec. sorted table by descending ra. zoom in plot on ra < 19.5. highlight a row where ra > 150.. nothing show(good). then selected the same row.. a green dot shows(bad).
• when X/Y ratio is large.. plot overflow.. but, have no way to scroll.
  mouse drag to select an area. no way to unselect it. i assume a click will unselect it. but, it does not.
• set x-bin and y-bin to 500, legend no longer show the color, only label.

[loitly]

adding simple comments like these in this function really helps. it was hard to read without it.

[loitly]

Looks good.