Code review feedback changes.

* Add `anyhow` dependency to `wasmtime-runtime`.
* Revert `get_data` back to `fn`.
* Remove `DataInitializer` and box the data in `Module` translation instead.
* Improve comments on `MemoryInitialization`.
* Remove `MemoryInitialization::OutOfBounds` in favor of proper bulk memory
  semantics.
* Use segmented memory initialization except for when the uffd feature is
  enabled on Linux.
* Validate modules with the allocator after translation.
* Updated various functions in the runtime to return `anyhow::Result`.
* Use a slice when copying pages instead of `ptr::copy_nonoverlapping`.
* Remove unnecessary casts in `OnDemandAllocator::deallocate`.
* Better document the `uffd` feature.
* Use WebAssembly page-sized pages in the paged initialization.
* Remove the stack pool from the uffd handler and simply protect just the guard
  pages.

crates/runtime/Cargo.toml

@@ -25,6 +25,7 @@ backtrace = "0.3.55"
 lazy_static = "1.3.0"
 psm = "0.1.11"
 rand = "0.7.3"
+anyhow = "1.0.38"
 
 [target.'cfg(target_os = "windows")'.dependencies]
 winapi = { version = "0.3.7", features = ["winbase", "memoryapi", "errhandlingapi"] }