fixes #67210

We seem to use the readonly property way of exposing these values more widely. Standardizing this a bit across the codebase

* fix mac address issue

* add event for machineId disambig

* convert to async for readability

* address comments

* getMac - clean up timeout handling

* app - merge machine id handling into one

fixes #77226
fixes #67366

improve image source extraction for remote cases, https://github.com/kisstkondoros/gutter-preview/issues/57

Replace uses of `IDisposable[]` with a `DisposableStore`

#76442

For #76442

It appears that (running querySelector, getElementByTagName) that the
contents of electron's `<webviews>`, which contain the iframe, are
inaccessible. We were already disabling pointer events on iframes, this PR
makes sure we do so on webviews as well.