Extended notification behaviour

[Nexxed]

This will be in a few different parts as to not confuse each separate idea with one another.

Embed colours depending on Speedtest threshold

My gripe with the old project is that all Speedtest notifications on Discord all look the same.

If the the resulting embed changed colour depending on the result of the Speedtests and the thresholds that they trigger, that would make it easier to quickly run through the channel and spot bad Speedtests by associating a colour with them.

Custom notification providers

It would be quite powerful if we were able to determine our own format (request URL, body and method?) for Webhooks and use placeholder variables within them, perhaps as some type of "advanced mode"?

This way, for any notification services or Webhooks that require unusual GET/POST requests that the app doesn't already support, users will be able to make themselves, and by extension, customise the default messages for Discord, Slack, and so on by providing their own "schema" for a request.

Notification conditionals

Another powerful thing would be to emit a different notification if a certain threshold has been triggered for more than x times in a row. A common use case that I can see for this would be to, say, alert you via SMS or push notification (using a custom notification provider as explained above) when your Speedtests have been going below the "acceptable" threshold for three or more times in a row.