Handle missing a2a operations

[fjtirado]

A2A core functionalty (send/message, send/streaming, tasks/list, task/cancel and task/get) were implemented with #1087

In order to keep that PR reasonable small, not so frequent operations will be implementing with this PR:

• tasks/resubscribe
• tasks/pushNotificationConfig/set,
• tasks/pushNotificationConfig/get,
• tasks/pushNotificationConfig/list,
• tasks/pushNotificationConfig/delete,
• agent/getAuthenticatedExtendedCard

[HexCore8]

I discovered the Serverless Workflow community while exploring open-source projects and developer communities on GitHub. As I learned more about its mission and contributions to workflow automation and cloud-native technologies, I became interested in becoming part of the community.

What I like most about this community is its focus on innovation, collaboration, and open-source development. Serverless Workflow provides a platform for developers to share knowledge, contribute to meaningful projects, and learn about modern workflow orchestration and serverless technologies. I appreciate the welcoming environment that encourages learning and community participation.

I want to join the Serverless Workflow community because I am passionate about technology, open-source development, and continuous learning. I am eager to connect with experienced developers, contribute to projects, improve my technical skills, and gain practical experience working with cloud-native solutions. I believe this community will help me grow as a developer while allowing me to contribute positively to the ecosystem.