Resotre cursor position when sorting

Also copy the content when sorting

Ref #67

autoload/vista.vim

@@ -34,7 +34,14 @@ function! vista#Sort() abort
   endif
   let provider = t:vista.provider
   let cache = vista#executive#{provider}#Cache()
-  call vista#sidebar#Reload(vista#viewer#Render(cache))
+
+  let cursor_position = getpos('.')
+
+  call vista#sidebar#Reload(cache)
+
+  if cursor_position != getpos('.')
+    call setpos('.', cursor_position)
+  endif
 endfunction
 
 function! vista#RunForNearestMethodOrFunction() abort

autoload/vista/executive/coc.vim

@@ -95,7 +95,7 @@ function! s:Dispatch(F, ...) abort
 endfunction
 
 function! vista#executive#coc#Cache() abort
-  return get(s:, 'cache', {})
+  return get(s:, 'data', {})
 endfunction
 
 " Internal public APIs

autoload/vista/executive/ctags.vim

@@ -286,7 +286,7 @@ function! s:Dispatch(F, ...) abort
 endfunction
 
 function! vista#executive#ctags#Cache() abort
-  return get(s:, 'cache', {})
+  return get(s:, 'data', {})
 endfunction
 
 " Run ctags given the cmd synchronously

autoload/vista/renderer/default.vim

@@ -183,7 +183,7 @@ function! s:RenderScopeless(scope_less, rows) abort
     let lines = scope_less[kind]
 
     if get(t:vista, 'sort', v:false)
-      call sort(lines, function('s:Compare'))
+      let lines = sort(copy(lines), function('s:Compare'))
     endif
 
     for line in lines

autoload/vista/renderer/kind.vim

@@ -45,12 +45,12 @@ function! s:viewer.render() abort
     " Parent
     call add(self.rows, parent)
 
-    if get(t:vista, 'sort', v:false)
-      call sort(v, function('s:Compare'))
-    endif
-
     if !empty(v)
 
+      if get(t:vista, 'sort', v:false)
+        let v = sort(copy(v), function('s:Compare'))
+      endif
+
       " Children
       for i in v
         if len(i) > 0