refactor(css): add styles targeting SVG button/modal icons (#1464)

* refactor(css): add global classes for common icon types

* refactor(css): target child SVGs instead of creating new icon classes

* fix: fix ButtonWithDropdown style class spacing

src/components/StatusChacker/index.tsx

@@ -39,7 +39,7 @@ const StatusChecker: React.FC = () => {
       show={data.commitTag !== process.env.commitTag}
     >
       <Modal
-        iconSvg={<SparklesIcon className="w-6 h-6" />}
+        iconSvg={<SparklesIcon />}
         title={intl.formatMessage(messages.newversionavailable)}
         onOk={() => location.reload()}
         okText={intl.formatMessage(messages.reloadOverseerr)}