Changed behaviour of adding token property. Added JSON export

[bubblobill]

Identify the Bug or Feature request

resolves #4768

Description of the Change

When there is a table row selected and adding a new property, the new property is inserted at the selected row
Exporting campaign properties now allows exporting as JSON
Added message on JSON export advising they cannot be imported.

Possible Drawbacks

none

Documentation Notes

Changed addTokenProperty behaviour to insert at selected row (where appropriate) instead of appending to the list.
Exporting campaign properties now allows exporting as JSON
Added message on JSON export advising they cannot be imported.

Release Notes

Adding a token property in campaign properties now adds the property at the selected row.
Exporting campaign properties now allows exporting as JSON.

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This change is 

[bubblobill]

#4649

[cwisniew]

@bubblobill maybe I am a bit daft, but whats the reasoning behind being able to export as JSON file if it can not be imported at a later time?

[fishface60]

@bubblobill maybe I am a bit daft, but whats the reasoning behind being able to export as JSON file if it can not be imported at a later time?

I could use it in generating documentation for my add-on by exporting to a file and having my documentation include it and parse it to generate a table.

I'll probably be parsing the content.xml of the unzipped .mtprops file instead though since I version control the properties of my add-on that way.

[bubblobill]

@bubblobill maybe I am a bit daft, but whats the reasoning behind being able to export as JSON file if it can not be imported at a later time?

JSON is considerably more human readable than xml. I've seen numerous requests where people want to see what's inside. For folk that want to get to grips with what's inside the box it's a friendlier place than exporting/unzipping/parsing xml/ then writing your own and reversing the process.

[cwisniew]

@bubblobill maybe I am a bit daft, but whats the reasoning behind being able to export as JSON file if it can not be imported at a later time?

JSON is considerably more human readable than xml. I've seen numerous requests where people want to see what's inside. For folk that want to get to grips with what's inside the box it's a friendlier place than exporting/unzipping/parsing xml/ then writing your own and reversing the process.

yeah but all of these requests are so they can edit it :)

[bubblobill]

It's a very non-obvious feature. You have to export the campaign and choose ".json" or ".txt" in the file filter dropdown to get it.
Choices:

1. Leave it.
2. Leave it and don't tell anybody it's there (undocumented feature)
3. Leave it but remove the file filters so you have to explicitly name a ".json" target file (undocumented feature).
4. Leave it and put a JSON import feature on the TODO list (tell me I'm not hilarious)
5. Leave it, put a JSON import feature on the TODO list, and declare a new ".universal_campaign_one_size_fits_all_VTT_format" to the world so they have to adopt our format.
6. Remove it