Double clicking on a lazy variable name to edit edits the preview instead of the value

[connor4312]

Testing #143572

1. Have a lazy variable with a value preview. In js-debug the preview is just the stringified function
2. Double click on the name of the variable to try to edit it
3. Get in this state where the getter is still collapsed and the value is being edited

Instead the variable should automatically expand and its value should be edited

[JacksonKearl]

In mock-debug this is surfaced as lazy var appearing on click and staying there after focus leaves

[roblourens]

Dupe of #143751