Alerts - Link dashboard and panel with configurable dashboard parameters

**Why is this needed**: When you have a dashboard that uses variables, then the default view of the dashboard may not immediately show the data that caused an alert. As the alert to dashboard linking does not allow for passing in dashboard variables, the user needs to take manual action to see the actual data that caused the alert. **Issue example** Consider a dashboard that monitors windows OS, which has a dashboard variable "hostname". The dashboard only shows data for the selected hostname. Now imagine that you're monitoring 100 different Windows machines and you have a single generic rule on CPU usage. If it exceeds 80% for longer than 5 minutes trigger an alert. Now when the alert triggers, the user gets a mail, clicks on the dashboard or panel link and ends up on the dashboard or panel. But because the dashboard uses variables, the default dashboard variables are selected. So the initial view that the user sees, does not relate to the Hostname that caused the alert to trigger. The hostname was available as a label on the metric. **What would you like to be added**: Ability to map any label available during the alert (either labels configured on the Alert itself, or coming from the Metric that caused the alert) to a Dashboard variable with the goal that the dashboard URL and panel URL is dynamically generated when the alert is firing. This applies to any feature that visualized the dashboard URL (email alerts, teams alerts, Alerts panel, etc). Example: Dashboard with dashboard variable Hostname exists. It contains the Hostname label values of metric "windows_cs_hostname". The dashboard has multiple panels which uses the hostname variable as filter. When creating an alert and selecting the linked dashboard and panel should allow to optionally configure the dashboard variables for the link. The values of the dashboard variables can either be a static value or a value from a label of the metric that triggered the alert. For the latter this means that the URL is…