Allow setting a priority on resolved Pushover notifications

[onedr0p]

Describe the feature request

It would be nice if I could set a separate priority for when alerts are resolved using Pushover.

Ideally I want alerts when triggered to be 1 (which is possible now) and when resolved 0 (not currently possible).

This is how Prometheus and Alertmanager currently operate for pushover for me:

priority: '{{ if eq .Status "firing" }}1{{ else }}0{{ end }}'

I would be over the moon if gatus could do something like that too.

Why do you personally want this feature to be implemented?

This would help cut down on alerting fatigue since some people might only be interested in getting alerted on problems at a higher priority and alerted on a lower priority when resolved.

How long have you been using this project?

18 months

Additional information

No response

[onedr0p]

@TwiN I would like to try and implement this but before I get started I am curious if you would be fine with the following config? The way alerting.pushover.priority-on-resolved would work is that it wouldn't be a breaking change to those using pushover already.

Configuring Pushover alerts

Parameter	Description	Default
alerting.pushover	Configuration for alerts of type pushover	{}
alerting.pushover.application-token	Pushover application token	""
alerting.pushover.user-key	User or group key	""
alerting.pushover.title	Fixed title for all messages sent via Pushover	Name of your App in Pushover
alerting.pushover.priority	Priority of all messages, ranging from -2 (very low) to 2 (emergency)	0
alerting.pushover.priority-on-resolved	Override the priority of messages on resolved, ranging from -2 (very low) to 2 (emergency)	alerting.pushover.priority
alerting.pushover.sound	Sound of all messages See sounds for all valid choices.	""
alerting.pushover.default-alert	Default alert configuration. See Setting a default alert	N/A