Update icons in about:debugging page

### Is your feature request related to a problem?

Icons in `about:debugging` page weren't updated on the release of Proton re-design (Firefox v89.0.0), but I think, that they should be updated.

Setup panel item icon:

Network location table icon:

Old extensions puzzle icons:

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#### Ditto, but corresponding SVGs:

Setup panel item icon:

Network location table icon:

Old extensions puzzle icon:

### The solution I'd like

#### Replace old icons with new icons:

For setup panel item:

For network location table:

For old extension puzzle icons:

### Screenshots or video

_No response_

### Alternatives I've considered

_No response_

### Additional context

_No response_

Begin at the about:debugging page and identify where its setup-panel, network-location table, and old-extension icons are styled. Done means all three icon groups use the requested replacements and the page matches the supplied references.

Written by the indexing model from the issue text.