disabled blocks lost when moving from text to blocks

[microbit-matt-hillsdon]

Describe the bug
Disabled blocks are lost when moving from text to blocks when there's been some kind of edit in text.

To Reproduce
Steps to reproduce the behavior:

1. New project
2. Drag a block onto the workspace
3. Switch to blocks
4. Add a comment
5. Switch back and note your disabled block is lost

I went looking for this as a potential similar issue to #6776 and spotted the code in patchBlocksFromOldWorkspace that's making a similar dubious check of "disabled" in the Blockly XML syntax (since v12 replaced by disabled-reasons).

To my surprise though, I can also repro this in v7. The last version where the disabled blocks are maintained for me is v6.

Expected behavior
Disabled blocks are maintained. That is my understanding of the intent of patchBlocksFromOldWorkspace (because the disabled blocks aren't represented as text).

Desktop (please complete the following information):

• OS: Mac
• Browser: Chrome
• Version: 146.0.7680.178 (Official Build) (arm64)