Add support for KB/s and fractional MB/s values for Net In/Out thresholds

[claytonjacobs]

Is your feature request related to a problem? Please describe.
Currently, Pulse only allows "Net In" and "Net Out" values to be configured in MB/s. This becomes an issue when you want to set smaller thresholds, such as 100 KB/s, since entering fractional values like 0.1 MB/s is not supported. This makes it difficult to monitor or control network traffic precisely for lower-bandwidth scenarios.

Describe the solution you'd like
I’d like the ability to select KB/s as an additional unit option for both "Net In" and "Net Out" measurements. Alternatively, Pulse could allow fractional MB/s inputs (e.g., 0.1 MB/s) to represent 100 KB/s. Either approach would make it easier to fine-tune network monitoring thresholds for smaller-scale transfers.

Describe alternatives you've considered
I initially tried setting the threshold to 0 and parsing the alert sent via Webhook to Home Assistant, but Pulse doesn’t allow 0 as a valid value, so this workaround isn’t possible.

Additional context
N/A