Fix TreeHelper problem when type and itemType are both the same

[LordSimal]

Fixes #267

The problem here was the fact, that simply checking

if ($rType === $type) {

doesn't determine if we are in a type or in a item.

This condition was built upon the fact, that both of these values are never the same.

To fix that I added a 4th parameter to the function which provides us the missing information (since we now where we are when we call the _attribute function)

Also the !empty($elementData['activePathElement']) fixes a warning which popped up for me.

[codecov-commenter]

Codecov Report

Merging #269 (06ec3e3) into master (af2fb41) will not change coverage. The diff coverage is 100.00%.

@@            Coverage Diff            @@
##             master     #269   +/-   ##
=========================================
  Coverage     78.88%   78.88%           
- Complexity     1830     1831    +1     
=========================================
  Files            62       62           
  Lines          4358     4358           
=========================================
  Hits           3438     3438           
  Misses          920      920           

Impacted Files	Coverage Δ
src/View/Helper/TreeHelper.php	82.27% <100.00%> (ø)

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[dereuromark]

Are you able to add a test case for this specific scenario?

[LordSimal]

Sure, let me do that quickly