[Bug][connector-v2][PulsarSource]can't consume messages all the time

[lightzhao]

Purpose of this pull request

Question: The running flag is not enabled all the time, so the message cannot be consumed.

Solution：Initialize setting running to true.

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
• Update the release-note.

[lightzhao]

@ashulin @Hisoka-X PTAL.

[lightzhao]

@ashulin PTAL.

[lightzhao]

@Hisoka-X @ashulin @TyrantLucifer PTAL.

[Hisoka-X]

LGTM

[lightzhao]

@EricJoy2048 @ashulin @TyrantLucifer PTAL.

[lightzhao]

@EricJoy2048 @ashulin @TyrantLucifer PTAL.

[lightzhao]

@ashulin PTAL.

[lightzhao]

@ashulin @TyrantLucifer PTAL.

[lightzhao]

@ashulin @ EricJoy2048 PTAL.

[lightzhao]

@EricJoy2048 @ashulin PTAL.

[lightzhao]

Hello everyone, who has the time to help with the review, the current bug has caused the pulsar source to fail to work normally, and the data cannot be consumed.

[Hisoka-X]

Hello everyone, who has the time to help with the review, the current bug has caused the pulsar source to fail to work normally, and the data cannot be consumed.

Thanks for push this PR, sorry for response slow.

[lightzhao]

Hello everyone, who has the time to help with the review, the current bug has caused the pulsar source to fail to work normally, and the data cannot be consumed.

Thanks for push this PR, sorry for response slow.
You are welcome, everyone who has time will review these pr #4302 #4246 #3990 , thank you.