[Feature]: Internal Add-On editor

[bubblobill]

Describe the Problem

Add-On development can be a pain because all the code needs to be written outside of MapTool. Every update requires the code to be updated, the add-on to be packaged up, then imported to MT.

This makes it much harder to tweak/diagnose code in the live environment.

The Solution you'd like

Add the ability to edit add-ons inside MapTool.

Something like the macro editor for script and other text files like .hbs, .css, and .js.

Alternatives that you've considered.

No response

Additional Context

No response

[FullBleed]

This is the biggest obstacle for Add-On adoption, imo.

And please:

1. Have the Add-On editor remember Find and Replace Search Bar visibility so it doesn't have to be toggled all the time.
2. Add "Copy/Paste" buttons.
3. And a "Get URI" button.