Rename OIDC components and variables to OAuth (#6686)

* Rename `OIDC` components and variables to `OAuth`. This matches the new behavior in the SDK.

libraries/oauth/test/build.gradle.kts

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2025 Element Creations Ltd.
+ * Copyright 2025 New Vector Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+plugins {
+    id("io.element.android-library")
+}
+
+android {
+    namespace = "io.element.android.libraries.oauth.test"
+}
+
+dependencies {
+    implementation(libs.coroutines.core)
+    api(projects.libraries.oauth.api)
+    implementation(projects.tests.testutils)
+}