Fix(agentflow) - Add iteration node full functionality (#6324)

* Fix output node not selectable

* Fix highlight color

* Fix previous node displaying label and not ID

* Fix tool arguements not being called

* Fix dropdown values to not be bold

* Add standard sizing for all input text

* FIx syntax highlighting styling

* Use predefined tokens for font weight and size

* Fix dialog size of Source

* Fix color of syntax highlight in dark mode

* Fix the input fileds color in dark and regular mode

* Fix gemini comments

* FIx inconsistent spacing

* Standardise gap between label and field

* Remove export for unused function and standardize dialog size accrosss code, rich text,
  and source

* Fix test error

* Fix opening node editing dialog on iteration node

* Untested change

* Add {{iteration}} variable

* Add node execution status to Iteration node

* Fix delete iteration node

* stream iteration node results incrementally when it is the terminal node

* Add test cases

* Fix edit color in dark mode and gemini comments

* Fix lint warnings

* Fix review comment - Add iterationEdge z-index value to tokens

* keep succesful and error messages in content

* Add removed comment

* Remove changes to server code in this PR