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>

tests/wpt/meta/IndexedDB/fire-success-event-exception.any.js.ini

@@ -5,7 +5,42 @@
   expected: ERROR
 
 [fire-success-event-exception.any.worker.html]
-  expected: CRASH
+  expected: TIMEOUT
+  [Exception in success event handler on request]
+    expected: TIMEOUT
+
+  [Exception in success event listener on request]
+    expected: TIMEOUT
+
+  [Exception in success event listener ("handleEvent" lookup) on request]
+    expected: TIMEOUT
+
+  [Exception in success event listener (non-callable "handleEvent") on request]
+    expected: TIMEOUT
+
+  [Exception in second success event listener on request]
+    expected: TIMEOUT
+
+  [Exception in first success event listener, tx active in second]
+    expected: TIMEOUT
+
 
 [fire-success-event-exception.any.html]
-  expected: CRASH
+  expected: TIMEOUT
+  [Exception in success event handler on request]
+    expected: TIMEOUT
+
+  [Exception in success event listener on request]
+    expected: TIMEOUT
+
+  [Exception in success event listener ("handleEvent" lookup) on request]
+    expected: TIMEOUT
+
+  [Exception in success event listener (non-callable "handleEvent") on request]
+    expected: TIMEOUT
+
+  [Exception in second success event listener on request]
+    expected: TIMEOUT
+
+  [Exception in first success event listener, tx active in second]
+    expected: TIMEOUT