Move "core" folder out of "features" into "base"

src/base/utils/ApplyStyles.ts

@@ -0,0 +1,15 @@
+/*
+ * Copyright (C) Contributors to the Suwayomi project
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+import { Theme } from '@mui/material/styles';
+
+// use CSSObject instead of SxProps<Theme> because this completely fucks over typescript by causing an out of memory error during compilation
+type CSSObject = ReturnType<Theme['applyStyles']>;
+
+const emptyStyle = {};
+export const applyStyles = (isActive: boolean, styling: CSSObject): CSSObject => (isActive ? styling : emptyStyle);