Improve ALE project style checking

* The project style linter now runs while you type.
* Now the scripts for checking the project require blank lines.
* Many style issues have been found and fixed.

ale_linters/dafny/dafny.vim

@@ -13,6 +13,7 @@ function! ale_linters#dafny#dafny#Handle(buffer, lines) abort
         \    'type': l:match[4] =~# '^Error' ? 'E' : 'W'
         \ })
     endfor
+
     return l:output
 endfunction