Move more test data to follow our conventions

Move more test data to follow our conventions

* test/data/minibuffer-test-cttq$tion: Move from here...
* test/lisp/minibuffer-resources/data/minibuffer-test-cttq$tion:
...to here.
* test/lisp/minibuffer-resources/lisp/cedet/semantic-utest-c.test:
* test/lisp/minibuffer-resources/lisp/cedet/semantic-utest.test:
New files.
* test/lisp/minibuffer-tests.el (ert, ert-x): Require.
(completion-table-test-quoting): Use ert-resource-directory.

* test/data/net/cert.pem:
* test/data/net/key.pem: Move frome here...
* test/lisp/net/network-stream-resources/cert.pem:
* test/lisp/net/network-stream-resources/key.pem: ...to here.
* test/lisp/net/network-stream-tests.el (ert, ert-x): Require.
(network-stream-tests--datadir): Remove variable.
(make-tls-server): Use ert-resource-file.

* test/data/vc/diff-mode/hello_emacs.c:
* test/data/vc/diff-mode/hello_emacs_1.c:
* test/data/vc/diff-mode/hello_world.c:
* test/data/vc/diff-mode/hello_world_1.c: Move from here...
* test/lisp/vc/diff-mode-resources/hello_emacs.c:
* test/lisp/vc/diff-mode-resources/hello_emacs_1.c:
* test/lisp/vc/diff-mode-resources/hello_world.c:
* test/lisp/vc/diff-mode-resources/hello_world_1.c: ...to here.
* test/lisp/vc/diff-mode-tests.el (ert, ert-x): Require.
(diff-mode-tests--datadir): Remove variable.
(diff-mode-test-font-lock-syntax-one-line)
(diff-mode-test-font-lock): Use ert-resource-directory.

* test/data/xdg/l10n.desktop:
* test/data/xdg/malformed.desktop:
* test/data/xdg/mimeapps.list:
* test/data/xdg/mimeinfo.cache:
* test/data/xdg/test.desktop: Move from here...
* test/lisp/xdg-resources/l10n.desktop:
* test/lisp/xdg-resources/malformed.desktop:
* test/lisp/xdg-resources/mimeapps.list:
* test/lisp/xdg-resources/mimeinfo.cache:
* test/lisp/xdg-resources/test.desktop: ...to here.
* test/lisp/xdg-tests.el (ert-x): Require.
(xdg-tests-data-dir): Remove variable.
(xdg-desktop-parsing, xdg-mime-associations): Use ert-resource-file.