Port and re-write icon code.

src/components/common/IconBase.tsx

@@ -0,0 +1,22 @@
+import { Attachment } from "revolt.js/dist/api/objects";
+import styled, { css } from "styled-components";
+
+export interface IconBaseProps<T> {
+    target?: T;
+    attachment?: Attachment;
+
+    size: number;
+    animate?: boolean;
+}
+
+export default styled.svg<{ square?: boolean }>`
+    img {
+        width: 100%;
+        height: 100%;
+        object-fit: cover;
+
+        ${ props => !props.square && css`
+            border-radius: 50%;
+        ` }
+    }
+`;