Delete SQLiteMode and deal with fallout

Delete SQLiteMode and deal with fallout

Summary:
This diff deletes the `SQLiteMode` in `typing_deps_mode.ml` which was being used for the legacy 32-bit dependency graph mode.

Then, I started deleting code until the build worked again. In particular I deleted:

1. Most of the stuff in `hh_shared.c` related to the 32-bit dep table
2. Most of the stuff in `serverLazyInit.ml` related to loading a 32-bit saved-state
3. Most of the stuff in `savedStateService.ml` related to loading and producing 32-bit saved-states
4. Stuff in `typing_deps.ml` related to interfacing with the 32-bit dep graph stored in shared-memory
5. Stuff in `SharedMem.DepTable` that (for some reason) was also used to interface with the 32-bit dep graph

Reviewed By: Wilfred

Differential Revision: D31689793

fbshipit-source-id: 69558ab8dbcf9ed586aa28b21f3d7ed7ca1f2bf0