[FEATURE]: Flusher plugin for Apache Doris

[xiaokang]

Concisely describe the proposed feature
We would like to add a flush plugin to store logs in Apache Doris. Apache Doris is a real-time data warehouse, which is also suitable for log storage.

Describe the solution you'd like (if any)
It may be similar to clickhouse flusher plugin . The flusher plugin will use an HTTP API called Stream Load to send data to Apache Doris.

Additional comments
N/A

[Takuka0311]

Thank you for your interest in the loongcollector community, and welcome your contribution. Please refer to the community documentation and existing plugins to guide your development. We look forward to seeing your flush plugin for Apache Doris! If you have any further questions or need assistance, feel free to reach out to the community.