wpView: improve handling of embed errors/error messages, see #28195

git-svn-id: https://develop.svn.wordpress.org/trunk@28754 602fd350-edb4-49c9-b593-d223f7449a82
TinyMCE wpView: fix selecting all of view's "text" in Safari, props avryl, fixes #28088

git-svn-id: https://develop.svn.wordpress.org/trunk@28755 602fd350-edb4-49c9-b593-d223f7449a82