Improve submission titles.

Many apps using the SEND intent for messages put a perspective title in the EXTRA_SUBJECT field. However, Diode doesn't check that field. This patch will check the EXTRA_SUBJECT field for a perspective title, but use the olg logic as a fallback.

The new logic. If there is data in both the EXTRA_SUBJECT and EXTRA_TEXT field, it will check to make sure that the EXTRA_TEXT is a valid URL. If so, it will use that data for submission. In this scenario is the EXTRA_SUBJECT fields is a blank string (as opposed to null value), I assume that the sending app meant to do that.

If there is no valid URL in EXTRA_TEXT, then it will use the old logic. If either field does not have data (null value as opposed to blank string), then it will use the old logic.

I've tested the new functionality, but I couldn't actually find a test case with the URL and the description in the EXTRA_TEXT field. I'm willing to regression test that part if you know how to replicate it.