This CL fixes some nits in TypeError messages, unifying the form of
kDefineDisallowed and kObjectNotExtensible to match what is used by the
majority of the other messages:
* "Cannot" vs. "Can't" -> choose "Cannot"
* "property:%" -> "property %"
* omit the full-stop at the end of the message
BUG=v8:5673
Review-Url: https://codereview.chromium.org/2686233008
Cr-Commit-Position: refs/heads/master@{#43150}