Replace `xs:sequence` by `xs:all`

[gotson]

Someone on Discord (i think @therobbiedavis) brought up the point that the current elements are contained in a xs:sequence.

The sequence would mean that (source):

The sequence element specifies that the child elements must appear in a sequence

• First, this doesn't really make sense from a domain perspective.
• Second, most consuming applications probably ignore that.

@ajslater brought up that we could replace it with xs:all, which represents an unordered list. It has an additional constraint in XSD 1.0 of limiting elements to 0 or 1 occurrence, but all the elements in the existing schema already have minOccurs="0" maxOccurs="1", so that's fine.

This would make the validation of the XML using the XSD schema easier, where it would probably throw errors if elements are out of order.

[gotson]

@ajslater @majora2007 would you confirm whether your respective parsers ignore the order of the elements? Komga doesn't care for sure.

[ajslater]

My parser doesn't pay attention to element order when reading comicinfo.xml.

[majora2007]

Kavita also does not pay attention to element order.

[IngBertolini]

Also why ComicPageType is defined as axs:list when a page can be only of one type?