GUI Library: datastorage table sorting

[AleksandrGorodetskii]

This PR adds the ability to sort the dataStorage table.

storage.listing.filter.items.limit preference will set a limit of files and folders for listing request (default = 1000).

default-sorting metadata tag will set default sorting for a bucket (column_key:order), for example: key = 'default-sorting' , value = 'name:asc' - column 'name' will be sorted by default (ascending order) key = 'default-sorting' , value = 'name' - if order ('asc'/'desc') is omitted, then 'desc' order will be applied by default to specified column. 'default-sorting' tag values (column_key:order) is case insensitive.

Available columns:

• name - file / folder name
• size - file size
• changed - file modified date