Add a function that waits for a port to show up

[jonathanhliu21]

Is your feature request related to a problem? Please describe.
N/A

Describe the solution you'd like
Add wait_for_port() in tools.py that waits for a certain port to show up or if no arguments are provided, waits for a new port to show up, then returns the port name.

Describe alternatives you've considered
N/A

Additional context
N/A