Capture/Replay: Capture entry point enum when possible. This should save on a few string comparisons. This CL also adds a helper function that converts from an entry point enum ID to a string entry point name. Bug: angleproject:3611 Change-Id: I47434235ca25203ef1d6814897d81afab444a7fd Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1719065 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>