Switch indexeddb backend to sqlite and improve IPC messaging (#38187)

- Use sqlite instead of heed. (one indexed database = one sqlite
database)
- Implement the backend for indexes
- Use keyranges where needed (as specified by the spec)
- Implement `getKey`
- Fix channel error messaging (led to a bunch of changes to how async
requests are handled)

Note: `components/net/indexeddb/engines/sqlite/serialize.rs` is unused;
I can delete it if needed.

Testing: Switching to sqlite eliminated many panics (exposing some new
failures).
Fixes: #38040

---------

Signed-off-by: Ashwin Naren <arihant2math@gmail.com>

components/script/indexed_db.rs

@@ -5,6 +5,7 @@
 use std::iter::repeat;
 use std::ptr;
 
+use ipc_channel::ipc::IpcSender;
 use js::conversions::jsstr_to_string;
 use js::gc::MutableHandle;
 use js::jsapi::{
@@ -14,17 +15,31 @@ use js::jsapi::{
 };
 use js::jsval::{DoubleValue, UndefinedValue};
 use js::rust::{HandleValue, MutableHandleValue};
-use net_traits::indexeddb_thread::{IndexedDBKeyRange, IndexedDBKeyType};
+use net_traits::indexeddb_thread::{BackendResult, IndexedDBKeyRange, IndexedDBKeyType};
+use profile_traits::ipc;
+use profile_traits::ipc::IpcReceiver;
 use script_bindings::conversions::{SafeToJSValConvertible, root_from_object};
+use script_bindings::root::DomRoot;
 use script_bindings::str::DOMString;
+use serde::{Deserialize, Serialize};
 
 use crate::dom::bindings::codegen::UnionTypes::StringOrStringSequence as StrOrStringSequence;
 use crate::dom::bindings::error::Error;
 use crate::dom::bindings::import::module::SafeJSContext;
 use crate::dom::bindings::structuredclone;
+use crate::dom::globalscope::GlobalScope;
 use crate::dom::idbkeyrange::IDBKeyRange;
 use crate::dom::idbobjectstore::KeyPath;
 
+pub fn create_channel<T>(
+    global: DomRoot<GlobalScope>,
+) -> (IpcSender<BackendResult<T>>, IpcReceiver<BackendResult<T>>)
+where
+    T: for<'a> Deserialize<'a> + Serialize,
+{
+    ipc::channel::<BackendResult<T>>(global.time_profiler_chan().clone()).unwrap()
+}
+
 // https://www.w3.org/TR/IndexedDB-2/#convert-key-to-value
 #[allow(unsafe_code)]
 pub fn key_type_to_jsval(
@@ -147,7 +162,6 @@ pub fn convert_value_to_key(
 
 // https://www.w3.org/TR/IndexedDB-2/#convert-a-value-to-a-key-range
 #[allow(unsafe_code)]
-#[expect(unused)]
 pub fn convert_value_to_key_range(
     cx: SafeJSContext,
     input: HandleValue,