fix sort for dir, tracks

[mikuta0407]

In the current implementation, if the file names are as follows, they will be output in the expected order when the client displays the list.

01 aaa.mp3
02 bbb.mp3
...
10 jjj.mp3
11 kkk.mp3
...
20 ttt.mp3
21 uuu.mp3

However, if the leading zero is not as shown below, iSub and Jamstash will sort by string instead of by track number.

1 aaa.mp3
2 bbb.mp3
...
10 jjj.mp3
11 kkk.mp3
...
20 ttt.mp3
21 uuu.mp3

↓

1 aaa.mp3
10 jjj.mp3
11 kkk.mp3.
...
2 bbb.mp3
20 ttt.mp3
21 uuu.mp3

This was resolved by inserting sort.

Also, DSub (Android) and others have a function to sort and display albums based on the release year value in the album list, but since Year is not stored when NewTCAlbumByFolder is executed in the GET /getMusicDirectory process, the value is not included in the HTTP response and year sorting is not possible, so this has been fixed.

[mikuta0407]

Oops... the test failed... I'll look into fixing that later.

[sentriz]

maybe we could just add an extra Order() to sort?

[mikuta0407]

As you pointed out, adding the order solved the problem. I added a commit in the fixup, so if there are no problems, I will squash it.
mikuta0407@e093113