migrate some components to Mui5 new styling system (#72)

* - Changed the value in Manga from 960 to 900( md breakpooint)
- The CicularLoader in About  and Reader screens is now centered to the whole screen
- Changed relative imports in About screen to absolute imports
- removed changed styles from Browse Screen, PageNumber

* Migrated Source Card, Extension Card and LoadingPlaceHolder to MUI system

* Migrated CategorySelect and LandSelect to using the sx prop

* migrated ReaderNavbar to mui 5

* - Removed Unused Styles from Page
- Migrated DoublePage, doublePagedPager, PagedPager, Vertical Pager and Horizontal Pager.

* Replaced style prop with sx prop

* removed useStyles completely from the project except for the Manga Screen

* added a comment

* Fixed the Source Card Buttons padding

* Removed the trailing backspace

Co-authored-by: Sascha Hahne <ntbm@users.noreply.github.com>

Co-authored-by: Sascha Hahne <ntbm@users.noreply.github.com>

src/components/reader/pager/VerticalPager.tsx

@@ -5,27 +5,15 @@
  * 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 makeStyles from '@mui/styles/makeStyles';
 import React, { useEffect, useRef } from 'react';
+import { Box } from '@mui/system';
 import Page from '../Page';
 
-const useStyles = makeStyles({
-    reader: {
-        display: 'flex',
-        flexDirection: 'column',
-        justifyContent: 'center',
-        margin: '0 auto',
-        width: '100%',
-    },
-});
-
 export default function VerticalReader(props: IReaderProps) {
     const {
         pages, settings, setCurPage, curPage, chapter, nextChapter, prevChapter,
     } = props;
 
-    const classes = useStyles();
-
     const selfRef = useRef<HTMLDivElement>(null);
     const pagesRef = useRef<HTMLDivElement[]>([]);
 
@@ -111,7 +99,16 @@ export default function VerticalReader(props: IReaderProps) {
     }, [pagesRef.current.length]);
 
     return (
-        <div ref={selfRef} className={classes.reader}>
+        <Box
+            ref={selfRef}
+            sx={{
+                display: 'flex',
+                flexDirection: 'column',
+                justifyContent: 'center',
+                margin: '0 auto',
+                width: '100%',
+            }}
+        >
             {
                 pages.map((page) => (
                     <Page
@@ -125,6 +122,6 @@ export default function VerticalReader(props: IReaderProps) {
                     />
                 ))
             }
-        </div>
+        </Box>
     );
 }