#13 Knxweb2: additional middle group sorting for object selection dropdown lists

[Fraxinas]

when somebody has multiple same subgroup address names in different middle groups and maybe even the same object type (for example the switch actor group address plus the feedback status groupd address for a certain light:

<object type="1.001" id="beleuchtung:switch:kitchen_ceiling" gad="5/4/211"  >Kitchen ceiling</object>
<object type="1.001" id="beleuchtung:status:kitchen_ceiling" gad="5/5/211" init="request" >Kitchen ceiling</object>

then it's impossible to see which of the two GADs is actually selected from the dropdown. so it would be a great improvement to either have optgroups for each seperate middle address or maybe add the middle address to the text line itself