Give Drydock leases a resourcePHID instead of a resourceID

Summary:
Ref T9252. Leases currently have a resourceID, but this is a bit nonstandard and generally less flexible than giving them a resourcePHID.

In particular, a resourcePHID is easier to use when rendering interfaces, since you can get handles out of a PHID.

Add a PHID column, copy over all the PHIDs that correspond to existing IDs, then drop the ID column.

Test Plan:

• Browsed web UIs.
• Inspected database during/after migration.
• Grepped for resourceID.
• Allocated a new lease with bin/drydock lease.

Reviewers: chad, hach-que

Reviewed By: hach-que

Maniphest Tasks: T9252

Differential Revision: https://secure.phabricator.com/D14151