Add ALERename (tsserver & LSP), ALEOrganizeImports (tsserver) and auto import support (tsserver) (#2709)

This commit adds support for renaming symbols in tsserver and with LSP tools, and for organising imports with tsserver. Completion results for symbols that can be imported are now suggested if enabled for tsserver completion done via ALE.

plugin/ale.vim

@@ -221,6 +221,12 @@ command! -nargs=1 ALESymbolSearch :call ale#symbol#Search(<q-args>)
 
 command! -bar ALEComplete :call ale#completion#GetCompletions('ale-manual')
 
+" Rename symbols using tsserver and LSP
+command! -bar ALERename :call ale#rename#Execute()
+
+" Organize import statements using tsserver
+command! -bar ALEOrganizeImports :call ale#organize_imports#Execute()
+
 " <Plug> mappings for commands
 nnoremap <silent> <Plug>(ale_previous) :ALEPrevious<Return>
 nnoremap <silent> <Plug>(ale_previous_wrap) :ALEPreviousWrap<Return>
@@ -259,6 +265,7 @@ nnoremap <silent> <Plug>(ale_find_references) :ALEFindReferences<Return>
 nnoremap <silent> <Plug>(ale_hover) :ALEHover<Return>
 nnoremap <silent> <Plug>(ale_documentation) :ALEDocumentation<Return>
 inoremap <silent> <Plug>(ale_complete) <C-\><C-O>:ALEComplete<Return>
+nnoremap <silent> <Plug>(ale_rename) :ALERename<Return>
 
 " Set up autocmd groups now.
 call ale#events#Init()