Make daemon loop over coordinator connection to make it possible to create a system service awaiting coordinator connection

[haixuanTao]

Loop over trying to connect to the coordinator on first connection to make it possible to await the coordinator to be ready.

This notably will make it possible to make dora daemon a system service which can

sudo tee /etc/systemd/system/dora-daemon.service << EOF
[Unit]
Description=Dora Daemon in Conda Environment
After=network.target

[Service]
Environment="PATH=$PATH"
User=HwHiAiUser
WorkingDirectory=/home/HwHiAiUser
ExecStart=/bin/bash --login  -c 'source /home/HwHiAiUser/.bashrc && source $CONDA_PATH/bin/activate base && dora daemon'
Restart=always
RestartSec=3
StartLimitInterval=60
StartLimitBurst=3

[Install]
WantedBy=multi-user.target
EOF

sudo systemctl daemon-reload
sudo systemctl enable dora-daemon.service
sudo systemctl start dora-daemon.service