Implement overview of used variables for Correlations and Data Validations

Right now, in LoadComplete you don't have an overview of used dynamic variables for correlations. You only see them when opening specific requests/responses. But that's hard to see if you have lot of requests and responses 'to manage'.

See below screenshot for the idea (global):

Also if possible, include links to the specific requests/responses (open them from the overview). Also include in the list the places where the variables are used in Data Validators.