Add ZMQ connection retry configuration

[zhengkezhou1]

fix: #141

introduces a configurable number of retries for ZMQ connections. Previously, connection failures would terminate the process, but this new setting allows for more resilient network communication.

[irar2]

@zhengkezhou1 Thanks for the PR!
Please add the new command line parameter to README, and please add a test to config_test.go

[irar2]

@zhengkezhou1 Please also add a test that actually checks the retries:
Don't start the sub, and try to start the pub, then after a delay start the pub and check that the publisher is successfully created.

Also, please validate that the number of retries is not negative (it can be set to a negative value in a config file - actually, I am not sure about that, maybe the fact that the field is uint is sufficient for yaml unmarshal to fail for negative values?).
And add a test that checks that invalid values are rejected (in config_test.go) both from command line and from a yaml file.

[zhengkezhou1]

@zhengkezhou1 Please also add a test that actually checks the retries: Don't start the sub, and try to start the pub, then after a delay start the pub and check that the publisher is successfully created.

The ZMQ Connect operation is asynchronous, which means it immediately returns success without waiting to establish a physical connection.

[zhengkezhou1]

I added a scenario here for when retries is a negative number.

[irar2]

Great, please also check what happens when it is set to a negative number in config file

[zhengkezhou1]

i add a new file invalid-config.yaml to address this. also test default value(0) in config.yaml

[irar2]

Great, please also check what happens when it is set to a negative number in config file

[irar2]

Thanks!