[IMPROVEMENT] UI design for playlist

[the-liquid-metal]

Currently, yt-dlp-gui display only the last item of playlist, although it able to scan the entire playlist items.

The suitable widget for this purpose is table or grid.

• Video option, audio option and filename input sould be aligned into a single row.
• There is no download button provided on each rows, nor individual button for video/audio option. A single "download all" button in the bottom of the table/grid.
• To accomodate user who wants to download video/audio individually, there is additional option item: "without video" in video option, and "without audio" in audio option.
• There is additional "detail button" on each rows which can refresh title and description fields.
• checkbox on each rows to indicate whether the row will be downloaded or not.

Additional features for playlist related:

• Change all video and change all audio. These are set of option and button. Change all video option consists of all individual video option items, and Change all audio option consists of all individual audio option items. If there is item that only available for some of video/audio, the text of the item should be appended with "(not all)". The button will apply to all rows (change individual video/audio option).
• File location button. Since clicking "browse" button on each rows is impractical, there should be main file location button.
• Reset button for all filename input. All individual input will be filled with its original title.
• Filename input pattern. This is set of input and button. There are predefined keywords which recognized by the input: "%title%", "%no%", "%date%", etc. The button will apply to all rows (change individual input with real filename). user can still modify the input after this button is clicked.
• Check-all and uncheck-all buttons, or a single main checkbox to toggle all other checkboxes.
• Export button. This will produce the state of everything inside the table/grid in the form of CSV or JSON.

Note:

• This design can also be applied to single movie. At first, yt-dlp-gui does not khow whether the pasted url is a single movie or a playlist. If there is a single movie, then yt-dlp-gui only display a single row in the table.
• There should be visually invalid marker for filename in case of duplicate names. This visual marker can be in the form of error icon and/or red background color.