org-element: Small change to src block indentation
* lisp/org-element.el (org-element-remove-indentation): Renamed from
`org-element--remove-indentation'.
(org-element-example-block-interpreter, org-element-src-block-parser):
Do not depend on `org-src-preserve-indentation'.
(org-element-src-block-interpreter, org-element-example-block-parser):
Check `org-src-preserve-indentation'.
* lisp/ox.el (org-export-unravel-code): Handle
`org-src-preserve-indentation'.
* testing/lisp/test-org-element.el: Update tests.