[Feature][Connector V2] add gitlab source connector

[liugddx]

Purpose of this pull request

Check list

• Code changed are covered with tests, or it does not need tests for reason:
• If any new Jar binary package adding in your PR, please add License Notice according
  New License Guide
• If necessary, please update the documentation to describe the new feature. https://github.com/apache/incubator-seatunnel/tree/dev/docs
• If you are contributing the connector code, please check that the following files are updated:
  1. Update change log that in connector document. For more details you can refer to connector-v2
  2. Update plugin-mapping.properties and add new connector information in it
  3. Update the pom file of seatunnel-dist

[liugddx]

#3018

[liugddx]

test result .

[liugddx]

env {
  # You can set flink configuration here
  execution.parallelism = 1
  job.mode = "STREAMING"
  #execution.checkpoint.interval = 10000
  #execution.checkpoint.data-uri = "hdfs://localhost:9000/checkpoint"
}

source {
  # This is a example source plugin **only for test and demonstrate the feature source plugin**
  Gitlab{
    url = "https://gitlab.com/api/v4/projects"
    access_token = "xxxx"
    schema {
      fields {
        id = int
        description = string
        name = string
        name_with_namespace = string
        path = string
        http_url_to_repo = string
      }
    }
  }

  # If you would like to get more information about how to configure seatunnel and see full list of source plugins,
  # please go to https://seatunnel.apache.org/docs/category/source-v2
}

transform {


  # If you would like to get more information about how to configure seatunnel and see full list of transform plugins,
  # please go to https://seatunnel.apache.org/docs/category/transform
}

sink {
  Console {
    parallelism = 1
  }

  # If you would like to get more information about how to configure seatunnel and see full list of sink plugins,
  # please go to https://seatunnel.apache.org/docs/category/sink-v2
}

[liugddx]

@TaoZex @EricJoy2048 @TyrantLucifer @Hisoka-X PTAL thanks.

[TaoZex]

Please Add e2e test.

[liugddx]

Please Add e2e test.
It contains sensitive information and cannot be disclosed.

[TaoZex]

reference
#3340

mock http server to add e2e test

[liugddx]

reference #3340

mock http server to add e2e test

this mock test has covered the http use case.This connector is only for gitlab

[liugddx]

The test of restful api focuses on request rules, not result parsing.Can we store keys in Actions secrets and replace them with config?
https://docs.github.com/cn/actions/security-guides/security-hardening-for-github-actions#overview

@TaoZex @EricJoy2048 @hailin0

[liugddx]

The test of restful api focuses on request rules, not result parsing.Can we store keys in Actions secrets and replace them with config? https://docs.github.com/cn/actions/security-guides/security-hardening-for-github-actions#overview

@TaoZex @EricJoy2048 @hailin0

@ashulin @Hisoka-X @CalvinKirs @TyrantLucifer Please give us some advice.

[liugddx]

@hailin0 @EricJoy2048 PTAL

[hailin0]

add this method

    @Override
    public Boundedness getBoundedness() {
        if (JobMode.BATCH.equals(jobContext.getJobMode())) {
            return Boundedness.BOUNDED;
        }
        throw new UnsupportedOperationException(xxx);
    }