R1:0d9362355b1e

In ApplicationTransactionEditor, determine new objects with "getID()" instead of "getPHID()"

Summary:
See <https://discourse.phabricator-community.org/t/unable-to-reload-object-that-hasnt-been-loaded/2677>.

When editing "Config" objects, they currently get a PHID set outside of the TransactionEditor. They probably should not, but fixing that is likely an involved change.

This causes us to incorrectly fail to detect `$is_new` correctly and try to `reload()` and object with no ID.

To work around this…