[PATCH v2 2/7] test: emacs: new tests "notmuch-show: {, un}collapse all messages in thread"

* test/emacs: - New subtest "notmuch-show: collapse all messages in thread": `notmuch-show-open-or-close-all' with prefix arg ("C-u M-RET") collapses all messages in thread. - New subtest "notmuch-show: uncollapse all messages in thread": `notmuch-show-open-or-close-all' without

[PATCH v2 2/7] test: emacs: new tests notmuch-show: {, un}collapse all messages in thread

* test/emacs: - New subtest notmuch-show: collapse all messages in thread: `notmuch-show-open-or-close-all' with prefix arg (C-u M-RET) collapses all messages in thread. - New subtest notmuch-show: uncollapse all messages in thread: `notmuch-show-open-or-close-all' without prefix