Move skillmap projects to the editor workspace

[riknoll]

Moving all of the skillmap projects from outside the editor iframe to inside! List of changes includes:

1. Skillmap headers are now saved along all of the other editor projects with a flag to filter them out of "my projects"
2. When we load the workspace, skillmap projects are automatically imported and soft-deleted from the skillmap workspace
3. All code carryover project merging now happens inside the iframe when the tutorial is loaded
4. Created some new tutorial events for reporting progress from the editor to the MakecodeFrame
5. The skillmap now has the webconfig embedded in the HTML file and points to the correct target version instead of the embedURL for the iframe
6. The "start fresh"/"keep code" dialog now shows before we load the editor instead of after

Here's a test upload:

• editor
• skillmap

Note: If you open this editor/skillmap upload, all of your skillmap tutorial projects will suddenly show up in the beta/released editor. The code to filter skillmap projects out of "My Projects" is part of this PR

TODO:

1. Now that the dialog is before the editor load, we should start loading the editor in the background to improve perf
2. I need to fix the loading editor event so that you don't ever see "starting tutorial" when opening an activity

[shakao]

is it weird to have two subsequent modals like this? do the modals look different enough that kids won't just rapidly click on the rightmost button twice in a row? (probably a thing to discuss/fix in a later pr)

[riknoll]

I think we should maybe take a look at it in a design meeting; could be confusing.

[shakao]

hmm the completion modal/confetti autodisplay doesn't seem to be happening in the builds here