ob-exp: Fix switches handling upon exporting
* lisp/ob-exp.el (org-babel-exp-code-template): Include switches in
template.
(org-babel-exp-code): Provide %switches placeholder.
* testing/lisp/test-ob-exp.el (ob-export/export-src-block-with-switches):
New test.
(ob-export/export-src-block-with-flags): Fix indentation.
This fixes
dde6af3a6230b37aabfb4f75c2dee89433958375. The confusion
came from the fact that "flags" placeholder had two meanings:
the :flags value and the block's switches (e.g., "-n"). This patch
separates these two meanings.