Auto merge of #13612 - szeged:test-api-impl, r=jdm

WebBluetooth Test API and tests

<!-- Please describe your changes on the following line: -->

This patch depends on the [devices mock device support PR](https://github.com/servo/devices/pull/17).
After it lands, the Cargo files can be updated.
1. Adjust to the changes in [devices mock device support PR](https://github.com/servo/devices/pull/17).
2. WebBluetooth Test API implementation. Based on : https://webbluetoothcg.github.io/web-bluetooth/tests.html
3. Wpt tests for the already landed WebBluetooth functions.

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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors

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- [x] There are tests for these changes

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resources/gatt_blacklist.txt

@@ -40,6 +40,9 @@ f000ffc0-0451-4000-b000-000000000000
 # Block access to standardized unique identifiers, for privacy reasons.
 00002a25-0000-1000-8000-00805f9b34fb
 
+# Blacklisted characteristic used to test readValue function.
+bad1c9a2-9a5b-4015-8b60-1579bbbf2135 exclude-reads
+
 
 ## Descriptors
 
@@ -50,4 +53,10 @@ f000ffc0-0451-4000-b000-000000000000
 
 # org.bluetooth.descriptor.gatt.server_characteristic_configuration
 # Writing to this would let a web page interfere with the broadcasted services.
-00002903-0000-1000-8000-00805f9b34fb exclude-writes
+00002903-0000-1000-8000-00805f9b34fb exclude-writes
+
+# Blacklisted descriptor used to test.
+07711111-6104-0970-7011-1107105110aaa
+
+# Blacklisted descriptor used to test.
+aaaaaaaa-aaaa-1181-0510-810819516110 exclude-reads

resources/package-prefs.json

@@ -1,5 +1,6 @@
 {
   "dom.bluetooth.enabled": false,
+  "dom.bluetooth.testing.enabled": false,
   "dom.forcetouch.enabled": true,
   "dom.mouseevent.which.enabled": false,
   "dom.mozbrowser.enabled": true,

resources/prefs.json

@@ -1,5 +1,6 @@
 {
   "dom.bluetooth.enabled": false,
+  "dom.bluetooth.testing.enabled": false,
   "dom.forcetouch.enabled": false,
   "dom.mouseevent.which.enabled": false,
   "dom.mozbrowser.enabled": false,