[feature] Added support for association to multiple file extensions

[alexmercerind]

Now --fe commandline argument can receive args as follows to associate with multiple file extensions. (Separated with commas).

flutter pub run msix:create --fe ogg,ogx,aac,m4a,mp3,wma,wav,aiff,flac,opus

Following section of XML is generated.

          <uap:Extension Category="windows.fileTypeAssociation">
            <uap:FileTypeAssociation Name="fileassociations">
              <uap:SupportedFileTypes>
                <uap:FileType>.ogg</uap:FileType>
                <uap:FileType>.ogx</uap:FileType>
                <uap:FileType>.aac</uap:FileType>
                <uap:FileType>.m4a</uap:FileType>
                <uap:FileType>.mp3</uap:FileType>
                <uap:FileType>.wma</uap:FileType>
                <uap:FileType>.wav</uap:FileType>
                <uap:FileType>.aiff</uap:FileType>
                <uap:FileType>.flac</uap:FileType>
                <uap:FileType>.opus</uap:FileType>
              </uap:SupportedFileTypes>
            </uap:FileTypeAssociation>
          </uap:Extension>

Support for single file extension will keep working the same way.

Notes

• I have confirmed the functioning.
• In case the extensions provided by user begin with a period (.), it will be automatically handled.

Lastly, thanks a lot for this great project, really a life saver.

Thankyou.

Look forward for any requested changes to get this merged.

[YehudaKremer]

fix white space bug:

[YehudaKremer]

thank you @alexmercerind for your contribution 👍

[YehudaKremer]

version 2.1.3 is now available.