[Feature Request]: Better Custom Sorting in Playlists

### Guidelines

- [x] I have [searched the issue tracker for open and closed issues](https://github.com/FreeTubeApp/FreeTube/issues?q=is%3Aissue+sort%3Arelevance-desc) that are similar to the feature request I want to file, without success.
- [x] I have searched the [documentation](https://docs.freetubeapp.io/) for information that matches the description of the feature request I want to file, without success.
- [x] This issue contains only one feature request.
- [x] I have read and agree to follow the [rules](https://docs.freetubeapp.io/community/rules/).

### Problem Description

Currently, custom sorting in playlists can be very arduous, requiring many clicks to get videos where they need to be.

### Proposed Solution

As a generalisation of the already proposed dragging and dropping (#4872), I'd like to propose something similar to Steam's wishlist sorting, which not only allows for dragging and dropping items (though not moving items up or down once like the current version of FreeTube), but shows an editable field with the index of the item in the list and allows one to instantly insert an item anywhere in the list just by changing it (with 0 bringing it to the front and any number larger than the length of the list taking it to the very bottom).

The combination of these three options gives the most flexibility and would improve the accessibility of the custom sorting feature massively. The current setup is not only tedious but can cause chronic pain issues to flare up (both with mouse and keyboard controls), while dragging and dropping can be even more inaccessible than the up/down buttons to some like me where it requires holding a physical button down without break for a long time to move videos in a long playlist; they are both very intuitive compared to just changing index numbers, though, so a mix of features seems best to me, particularly with how Steam has shown two of the three to work excellently together.

### Alternatives Considered

None that come to mind, aside from continuing to use the current sorting feature, potentially to the detriment of one's physical wellbeing if the list gets long (as well as being annoying to use), or not using custom sorting at all.

### Issue Labels

ease of use improvement

### Additional Information

An example of Steam's wishlist UI, with the index field of the first item in editing mode. The entire left side can be grabbed to allow for resorting via dragging and dropping, changing the index numbers to match afterwards.