Specify request URL to the API for inserting and fetching datapoints

The way the signal strength threshold is enforced may be problematic and cause the application to count the wrong number of devices.

This will happen all of the following happens:

1. A device enters the vicinity of the threshold and triggers a DeviceAdded event
2. The device goes outside the threshold but stays within the vicinity of the host device, not causing a DeviceRemoved event.

This is a critical bug because it may cause the application to gather bad data during training.

The bluer library which is used doesn't seem to provide any way to continuously check the signal strength of connected devices. Therefore it is likely that this library will need to be replaced. I don't know any other way of fixing it.

create an option to run without any signal threshold

Inspired by htop, pin the number of connected devices to its own section of the stdout while outputting the event log in it's own section

tui-rs can be used to achieve this

since - is a reserved character for specifying args, the program cannot parse the threshold CLI arg properly when given a negative number

The way to mitigate this issue is to use the --argname=argvalue syntax, i.e --threshold=-75

There should be an instruction telling you to use this syntax or be implemented a solution that parses it properly when used in this manner --threshold -75