Fix/manga screen prevent fab from overlaying last chapter in list (#298)

* Introduce "StyledFAb"

MUI "Fab" with the "default" styling applied

* Prevent FAB from overlaying last chapter in list of Manga details page

src/components/util/StyledFab.tsx

@@ -0,0 +1,17 @@
+import { Fab } from '@mui/material';
+import { styled } from '@mui/system';
+
+export const DEFAULT_FAB_STYLE = {
+    position: 'fixed',
+    height: '48px',
+    right: '3em',
+    bottom: '2em',
+} as const;
+
+export const DEFAULT_FULL_FAB_HEIGHT = `calc(${DEFAULT_FAB_STYLE.bottom} + ${DEFAULT_FAB_STYLE.height})`;
+
+const StyledFab = styled(Fab)({
+    ...DEFAULT_FAB_STYLE,
+}) as typeof Fab;
+
+export default StyledFab;