Fix #4030: add copy module option for add existing module function.

[zyhfish]

Fix #4030: add copy module option for add existing module function.

[sbwalker]

@zyhfish my preference for implementing this feature is that we keep the UI very simply and consistent with the approach used currently. I would simply add a "Copy Existing Module" option to the first option in Module Management:

This new option will behave similar to "Add Existing Module" ie. it will allow you to select a Page/Module:

However, copy is only possible if a module implements IPortable - so the list of modules should either be filtered so that modules which do not support IPortable are not displayed (ie. using module.ModuleDefinition.IsPortable) or the system should allow a user to select the module and then provide feedback in the existing message area that the module does not support the ability to be copied. The first option prevents users from selecting certain modules but may result in users logging issues because they think the behavior is a bug. The second option displays all modules and provides explicit feedback to the user which offers better transparency and clarity - so is probably the better approach.

I realize that for some folks with a DNN background, the technical concepts of "sync", etc... makes sense, however Oqtane is focused on a broader audience so I would prefer to not follow the DNN patterns.

[zyhfish]

Hi @sbwalker , thanks so much for the update, the code has been updated, could you please help to check again? I also noticed that some times control panel was hidden but the mask still display, this may need open another ticket to analyze.

[sbwalker]

@zyhfish I will merge this PR and make some minor adjustments