Make Drydock blueprint create workflow somewhat more standard

Summary: Ref T2015. This workflow is a little weird (runs in a dialog, no edit-before-create step, lots of internal classnames). Make it a little more standard.

Test Plan: See screenshots.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2015

Differential Revision: https://secure.phabricator.com/D7908