Action Type
Description: Action to be performed on the element
Syntax:
| ■ | modify: sets element to new value (all element types) | 
| ■ | add-prefix: adds value at beginning of string (string element only) | 
| ■ | remove-prefix: removes value from beginning of string (string element only) | 
| ■ | add-suffix: adds value at end of string (string element only) | 
| ■ | remove-suffix: removes value from end of string (string element only) | 
| ■ | add: adds a new header/param/body (header or parameter elements) | 
| ■ | remove: removes a header/param/body (header or parameter elements) |