selectableRowsRangeMode and deselect row

[liedekef]

Is your feature request related to a problem? Please describe.*
Currently, when using the option selectableRowsRangeMode=click, one can not deselect a row by clicking on it. Even more, the checkbox rendered by using the formatter rowSelection is not clickable/working. One must use ctrl-click to deselect a row.
This is very counter-intuitive but currently works as designed.

Describe the solution you'd like
In the code of the function handleComplexRowClick , there are 2 sections currently handled when using the ctrl-click :
if(e.ctrlKey || e.metaKey){
Now changing those lines to just if(true) (and ignoring the "else", for sake of testing), the select/deselect/shift-select starts working much more intuitive.
So I would propose one of two things:

• either remove the ctrl-if statement and keep the more intuitive behavior (or swith the ctrl-if and the else-section around)
• or, to keep backwards compatibility, create a new option value: selectableRowsRangeMode=mixedClick (or something alike), which does the same as the "click" but using the ctrl-click as normal behavior