Remove transient behavior of filters for table

[ckuenne]

Currently features can be sub-selected from the top table by clicking on a row or by chosing a number of top/bottom features. This sub-selection is transient, i.e. it does not really change the underlying list, which seems to confuse many users. It would be nicer if we had i.e. a separate "selection" column with tick marks that clearly show which features are selected right now. and this column could be automatically updated based on the feature selector. or is there a better way?

Maybe this might help?
https://jrowen.github.io/rhandsontable/
https://swechhya.github.io/excelR/

ps. actually i guess there should be two selection lists, the second being the highlighting list. and none of these should be transiently filtered.