#3332 Implement :ALERename! for ignoring errors

:ALERename! now ignores errors for files that cannot be modified, and
modifies all other files.

test/test_organize_imports.vader

@@ -57,9 +57,9 @@ Before:
     call add(g:expr_list, a:expr)
   endfunction
 
-  function! ale#code_action#HandleCodeAction(code_action, should_save) abort
+  function! ale#code_action#HandleCodeAction(code_action, options) abort
     let g:handle_code_action_called = 1
-    AssertEqual v:false, a:should_save
+    Assert !get(a:options, 'should_save')
     call add(g:code_actions, a:code_action)
   endfunction