Fix invisible chat icons (#10406)

As of #10393 some icons in the chat were invisible, looking at the icons
I noticed that the viewport was actually 800x800, I scaled that down to
16x16 and now they work fine again.

Also remove the `reply_arrow_left` icon because it is not used at all.

Thanks to @RemcoSmitsDev for noticing.

I don't have any expertise in svg's, so if something is off about the
svg markup reach out to me.

Release Notes:

- N/A

crates/ui/src/components/icon.rs

@@ -103,7 +103,6 @@ pub enum IconName {
     ReplaceNext,
     Return,
     ReplyArrowRight,
-    ReplyArrowLeft,
     Settings,
     Screen,
     SelectAll,
@@ -200,7 +199,6 @@ impl IconName {
             IconName::ReplaceNext => "icons/replace_next.svg",
             IconName::Return => "icons/return.svg",
             IconName::ReplyArrowRight => "icons/reply_arrow_right.svg",
-            IconName::ReplyArrowLeft => "icons/reply_arrow_left.svg",
             IconName::Settings => "icons/file_icons/settings.svg",
             IconName::Screen => "icons/desktop.svg",
             IconName::SelectAll => "icons/select_all.svg",