Allow configuration of product icons

[schtauffen]

The new expand/collapse icons are jarring for me and I would like to return to the smaller triangles.

I apologize if this is already doable, but I was unable to find it in the settings.

[gjsjohnmurray]

Not already doable, but similar already requested in #78024 (comment) for code-folding icons.

[ErikHumphrey]

Would adding this level of theming heavily increase load times?

Edit: Nice! Let's make all icons configurable, then.

[miguelsolorio]

@ErikHumphrey we already do this with file icons so it shouldn't impact performance

[Hum4n01d]

I would really appreciate an option to used the filled versions of the icons, maybe create an official icon extension with them?

[kiprasmel]

If we can have a filled-in version of the current icons, how about also having the old icons available?

Or maybe allowing users to choose their own icons, so that you could cherry-pick from the new ones, the old ones and even select your own?

The activity bar would be a great start IMO, because I dislike the new ones, and would love the option to switch back.

[lllopo]

Hopefully, if you revert to the old triangles, you make it optional, as the chevrons are much, much better looking to me. Actually the triangles were the most ugly thing in the whole VS Code interface overall. The chevrons are great, they just need to be a bit smaller as currently are too imposing.

[unixcow]

filled version of current icons sounds like a legit one, it will keep product identity the devs are looking for while make it more enjoyable for people who enjoyed the old (more solid) look