Move workspace comments into a plugin

[BeksOmega]

Category

• Plugins

Component

workspace-comments

Is your feature request related to a problem? Please describe.
Workspace comments exist in core, but they aren't really supported or documented. This is frustrating for external developers who want to use them. It is also frustrating for core developers because they aren't well-integrated.

Describe the solution you'd like
Move the workspace comments to a plugin.

Describe alternatives you've considered
N/A this is what plugins are for :P

Additional context
This should wait until after project-cereal is complete so that you can easily add serialization for the workspace comments.

Marking this as internal until there is serialization support in core.

[rachel-fenichel]

RaspberryPiFoundation/blockly#2724 has links to code in pxt-blockly and scratch-blocks that fix various issues that they found with workspace comments. I'm linking it as a resource in case of future bugs.

Some of the fixes are not applicable because we've changed other parts of code (including bindEventWithChecks) since writing workspace comments.

[rachel-fenichel]

RaspberryPiFoundation/blockly#1862 was also related: resizing a workspace comment should file an event.

[maribethb]

Related RaspberryPiFoundation/blockly#1674 asks what workspace comments should look like in generated code.