Derive icon paths (#17816)

This PR improves adding and working with icons by using the new
`DerivePathStr` to derive icon paths.

This means paths no longer need to be manually specified, and the
`IconName` and file name will always be consistent between icons.

This PR does not do any work to standardize icons visually, remove
unused icons, or any other such cleanup.

Release Notes:

- N/A

assets/icons/audio_off.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-volume-off"><path d="M16 9a5 5 0 0 1 .95 2.293"/><path d="M19.364 5.636a9 9 0 0 1 1.889 9.96"/><path d="m2 2 20 20"/><path d="m7 7-.587.587A1.4 1.4 0 0 1 5.416 8H3a1 1 0 0 0-1 1v6a1 1 0 0 0 1 1h2.416a1.4 1.4 0 0 1 .997.413l3.383 3.384A.705.705 0 0 0 11 19.298V11"/><path d="M9.828 4.172A.686.686 0 0 1 11 4.657v.686"/></svg>