Fix outline path position for org-roam-ref capture

[hwiorn]

Motivation for this change

Closes #2199

This PR needs PR #2336 to search correct OLP.

org-roam-ref-capture doesn't find correct the outline path when org-roam-capture--try-capture-to-ref-h is called. It needs to check ...+olp and goto-char to the OLP directly.

I think org-entry-end-position is not work when :prepend is nil, which means append actually. Because org-entry-end-position give you just end (before its subtree) of current entry instead of end of current whole entry including its subtree. That worked as prepend even if :prepend is nil.

[hwiorn]

I notice the 3 types of :prepend could be existed.
Currently, :prepend only two type, nil or t.

1. :prepend is nil (append)

* Note
  Some notes
  <- Add here: "** Something captured text 4"
** Something captured text 1
** Something captured text 2
** Something captured text 3

2. :prepend is t

* Note
  <- Add here: "** Something captured text 4"
  Some notes
** Something captured text 1
** Something captured text 2
** Something captured text 3

3. :prepend is after-subtree (which I'm trying to make it this PR)

* Note
  Some notes
** Something captured text 1
** Something captured text 2
** Something captured text 3
  <- Add here:  "** Something captured text 4"