Fix: #913: VimwikiGoto completion aafter <CR> [in input() prompt]

Issue #913:
        :VimwikiGoto tab completion only works when written in-line, not when called from \wn #913
        PR #785 adds completion to :VimwikiGoto, however it works only when you try to type the filename after the command, e.g.

Dockerfile

@@ -1,20 +1,20 @@
-FROM testbed/vim:17
+FROM testbed/vim:latest
 
-# add packages
-RUN apk --no-cache add bash=~5.0
-RUN apk --no-cache add git=~2.22
-RUN apk --no-cache add python3=~3.7
+# Add packages
+RUN apk --no-cache add bash
+RUN apk --no-cache add git
+RUN apk --no-cache add python3
 
-# get vint for linting
-RUN pip3 install vim-vint==0.3.21
+# Get vint for linting
+RUN pip3 install vim-vint
 
-# get vader for unit tests
+# Get vader for unit tests
 RUN git clone -n https://github.com/junegunn/vader.vim /vader
 WORKDIR /vader
 RUN git checkout de8a976f1eae2c2b680604205c3e8b5c8882493c
 
-# build vim and neovim versions we want to test
-# TODO uncomment nvim tag
+# Build vim and neovim versions we want to test
+# TODO add nvim tag
 WORKDIR /
 RUN install_vim -tag v7.3.429 -name vim_7.3.429 -build \
                 -tag v7.4.1099 -name vim_7.4.1099 -build \

autoload/vimwiki/base.vim

@@ -455,7 +455,9 @@ endfunction
 " Jump to other wikifile, specified on command mode
 " Called: by command VimwikiGoto (Exported)
 function! vimwiki#base#goto(...) abort
-  let key = a:0 > 0 ? a:1 : input('Enter name: ')
+  let key = a:0 > 0 ? a:1 : input('Enter name: ', '',
+        \ 'customlist,vimwiki#base#complete_links_escaped')
+
   let anchor = a:0 > 1 ? a:2 : ''
 
   " Save current file pos

test/command_goto.vader

@@ -1,3 +1,7 @@
+# Note: I dont know why <Tab> is inserting a Tab.
+#   Well better than to insert a Chair, but it should trigger completion
+#   So I used C-L
+
 Include: vader_includes/vader_setup.vader
 
 
@@ -17,7 +21,19 @@ Do (VimwikiGoto <CR> buzz_bozz && Assert):
   buzz_bozz\<CR>
   :AssertEqual $HOME . '/testmarkdown/buzz_bozz.md', expand('%')\<CR>
 
-Execute (:VimwikiGoto + Completion):
+Do (VimwikiGoto + Completion(cmdline) && Assert):
+  :VimwikiIndex 2\<CR>
+  :VimwikiGoto buzz_bo\<C-l>\<CR>
+  :AssertEqual $HOME . '/testmarkdown/buzz_bozz.md', expand('%')\<CR>
+
+Do (VimwikiGoto <CR> buzz_bo + Completion(input()) && Assert):
+  :VimwikiIndex 2\<CR>
+  :VimwikiGoto\<CR>
+  buzz_bo\<C-l>\<CR>
+  :AssertEqual $HOME . '/testmarkdown/buzz_bozz.md', expand('%')\<CR>
+
+
+Execute (:VimwikiGoto + Completion (API)):
   VimwikiIndex 2
   AssertEqual $HOME . '/testmarkdown/index.md', expand('%')
   let s_complete=string(vimwiki#base#get_globlinks_escaped())