Fix playing wrong item after deleting first item in playlist

[PikachuEXE]

Pull Request Type

• Bugfix
• Feature Implementation
• Documentation
• Other

Related issue

Closes #8579

Description

Fix playing wrong item after deleting first item in playlist (same as title
See issue for details
Caused by #5158 due to previous item assigned as first item in playlist after deletion (see example below)

Playlist before delete

• A
• B
• C

Playlist after delete

• B (problematic code points preview video to 1st item which is wrong)
• C

Screenshots

Lazy, test yourself

Testing

A. No shuffle
(1) First item

• Open random playlist
• Open 1st item in new window
• Go back to playlist delete 1st item
• Play next item to ensure it's 2nd item (well 1st item after playlist updated)
• Repeat last 2 steps but test playing prev item to ensure last item played

(2) Not first item

• Open random playlist
• Open nth (not 1st) item in new window
• Go back to playlist delete the same item
• Test play next/prev item to ensure it works as the same as before

B. No shuffle
Similar to (A)?

Desktop

• OS:
• OS Version:
• FreeTube version:

Additional context

[efb4f5ff-1298-471a-8973-3d47447115dc]

It has some issues with shuffle enabled

VirtualBoxVM_ZTRwXKlftK.mp4

VirtualBoxVM_UaWQzgYCGA.mp4

[PikachuEXE]

@efb4f5ff-1298-471a-8973-3d47447115dc Fixed the error

[efb4f5ff-1298-471a-8973-3d47447115dc]

New issue? Maybe underlying issue surfaced after fix?

VirtualBoxVM_fNiBTVr2Dt.mp4

[PikachuEXE]

Ok now I think I understand better on the shuffled items
The shuffling logic doesn't handle the case that when current video is removed from the playlist well, so a change is needed there
Please retest all shuffle cases