[[ Bug 18082 ]] Improve script only stack opening

[montegoulding]

This patch makes the following changes:

• Script only stacks will now be checked to determine if they are visible after opening before editing their script in the script editor after opening via the file menu and when opened via the system. This allows script only stacks that generate their own user interface via script in preOpenStack or openStack to not open into the script editor by setting the visible of the stack to true in openStack.
• StackFiles are now explicitly opened at startup by the IDE rather than depending on the engine to open them.
• StackFiles opened via AppleEvent will now use the same code path as StackFiles opened via command line arguments and relaunch arguments

[montegoulding]

Depends on this PR as otherwise the stacks will be loaded twice

[montegoulding]

Marking as WIP until the dependant PR is reviewed