Improve formatting of :set command output

[citizenmatt]

This PR fixes a few minor formatting issues with the output of the :set command:

• It removes the trailing spaces added to the end of the line for column padding
• It sorts option names before formatting, so the no prefix for boolean options isn't included
• Options with values (scrolloff=5) are formatted with a 2 char indent to line up with the boolean options
• Long options are not wrapped by the formatter, but expected to be wrapped by the output pane. The formatter doesn't have the actual width of the output pane, only the character width of the editor, which doesn't include line numbers and gutter width. The output pane can enable soft wraps to provide better wrapping
• Output in the same order as Vim, filling each column in turn, rather than filling multiple columns horizontally
• Support :set! to output options in a single column

[AlexPl292]

This looks good for me. Thank you for your changes!