Fix #190: sort candidates immediately after fetching them.

The :display-sort-function property in capf functions (vs the
'display-sort-function metadata property) doesn't appear to anything,
as pointed out by Felicián Németh.

* eglot.el (eglot-completion-at-point): Move location of sort function.

eglot.el

@@ -1834,7 +1834,11 @@ is not active."
                  (add-text-properties 0 1 all completion)
                  (put-text-property 0 1 'eglot--lsp-completion all completion)
                  completion))
-             items))))
+             (sort items
+                   (lambda (a b)
+                     (string-lessp
+                      (or (plist-get a :sortText) "")
+                      (or (plist-get b :sortText) ""))))))))
        :annotation-function
        (lambda (obj)
          (eglot--dbind ((CompletionItem) detail kind insertTextFormat)
@@ -1852,12 +1856,6 @@ is not active."
                        (and (eql insertTextFormat 2)
                             (eglot--snippet-expansion-fn)
                             " (snippet)"))))))
-       :display-sort-function
-       (lambda (items)
-         (sort items (lambda (a b)
-                       (string-lessp
-                        (or (get-text-property 0 :sortText a) "")
-                        (or (get-text-property 0 :sortText b) "")))))
        :company-doc-buffer
        (lambda (obj)
          (let* ((documentation