core: add support for unlink oauth account

packages/hydrooj/src/handler/home.ts

@@ -259,6 +259,13 @@ class HomeSecurityHandler extends Handler {
         await this.ctx.oauth.providers[platform].get.call(this);
     }
 
+    @param('platform', Types.String)
+    async postUnlinkAccount({ }, platform: string) {
+        if (!this.ctx.oauth.providers[platform]) throw new ValidationError('platform');
+        await this.ctx.oauth.unbind(platform, this.user._id);
+        this.back();
+    }
+
     @param('tokenDigest', Types.String)
     async postDeleteToken({ }, tokenDigest: string) {
         const sessions = await token.getSessionListByUid(this.user._id);