Below is an excerpt from my `~/.vimrc` that contains the vimscript code I implemented by building upon the very good "no new mappings" idea from the already [existing answer][1] provided by @the_velour_fog. 

I improved the idea and the implementation further to be almost something like "change nothing".  Just hit <kbd>'</kbd> or <kbd>`</kbd> as usual, and you'll get the list to select a mark from, but nothing else changes, not even the error messages displayed when trying to jump to unset or unknown marks. 

Actually, if you press <kbd>'</kbd> + <kbd>a</kbd> quickly, for example, or even <kbd>'</kbd> + <kbd>Esc</kbd> depending on the configured [`ttimeoutlen`][2] value, you may even not notice the list of marks being displayed for a fraction of a second, but still have the desired jump operation performed or canceled, or the original error message displayed.  That's how much the original behavior remains unchanged.

Here's the vimscript code:

```
" Display a list of marks and allow their easy selection, without
" remapping any keys or changing the original vim behavior, down
" to the error messages produced for unknown marks
"
function ListSelect(command, jump)
  execute a:command
  echohl Question
  echo "Enter mark (ESC to cancel): "
  echohl NONE
  let mark = nr2char(getchar())
  redraw
  if mark !=# "\e"
    try
      execute "normal! g" .. a:jump .. mark
    catch
      echohl ErrorMsg
      echo substitute(v:exception, "^Vim(.*):", "", "")
      echohl NONE
    endtry
  endif
endfunction

nnoremap <silent> ' :call ListSelect("marks", "'")<CR>
nnoremap <silent> ` :call ListSelect("marks", "`")<CR>
```

As visible in the vimscript code and as already described above, this version retains the ability to use <kbd>Esc</kbd> to cancel the whole operation, and it still produces the same `E20: Mark not set` and `E78: Unknown mark` error messages, without throwing any "executing function failed" errors at the user. 

This version also produces a prompt message that looks just like all such messages produced by `vim` itself, furthering the "change nothing" approach.

---

Below is an improved version of the above-provided vimscript code, which still follows the same "change nothing" approach.

This improved version mainly brings some vimscript-specific programming style improvements, such as using a [script-local function][3] and [`<SID>`][4] to avoid "polluting" the global space, and using [`<Cmd>`][5] for so-called "command mapping", which neatly executes commands without changing the current mode. 

This version also extends its support to visual mode, which unfortunately requires a small workaround that's described further in the comments below.

Here's the improved vimscript code:

```
" Display a list of the currently known marks and allow a mark to be
" selected from the list easily, without mapping any additional keys
" or changing the original vim behavior, down to still producing the
" original error messages for non-existent marks
"
" NOTE: A workaround is required in visual mode to produce the right
"       error message, because the message isn't displayed if jumping
"       to the non-existent mark is actually executed in visual mode,
"       which all works as expected in normal mode
"
function s:SelectMark(command)
  execute "marks"
  echohl Question
  echo "Enter mark (ESC to cancel): "
  echohl NONE
  let mark = nr2char(getchar())
  redraw
  if mark !=# "\e"
    try
      if mode("v:true") ==? "v" && line("'" .. mark) ==# 0
        throw "E20: Mark not set"
      endif
      execute "normal! " .. a:command .. mark
    catch
      echohl ErrorMsg
      echo substitute(v:exception, "^Vim(.*):", "", "")
      echohl NONE
    endtry
  endif
endfunction

nnoremap ' <Cmd>call <SID>SelectMark("'")<CR>
nnoremap ` <Cmd>call <SID>SelectMark("`")<CR>

xnoremap ' <Cmd>call <SID>SelectMark("'")<CR>
xnoremap ` <Cmd>call <SID>SelectMark("`")<CR>
```

I'll investigate further why the above-described workaround is needed, and possibly submit a patch for `vim` upstream.

[1]: https://vi.stackexchange.com/a/9746/48490
[2]: https://vi.stackexchange.com/questions/24925/usage-of-timeoutlen-and-ttimeoutlen
[3]: https://vimhelp.org/userfunc.txt.html#local-function
[4]: https://vimhelp.org/map.txt.html#%3CSID%3E
[5]: https://vimhelp.org/map.txt.html#%3CCmd%3E