add '--endpoint' to 'repro_cmd' for integrations

[bmc-msft]

Summary of the Pull Request

Updates crash report notifications repro_cmd to go from:

onefuzz repro create_and_connect container file

to:
onefuzz --endpoint https://INSTANCE.azurewebsites.net repro create_and_connect container file

This is extremely valuable to help users that support multiple OneFuzz instances.

PR Checklist

• Applies to work item
• CLA signed. If not, go over here and sign the CLI.
• Tests added/passed
• Requires documentation to be updated
• I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

Info on Pull Request

In addition to the aforementioned change to notifications, updates everywhere that was building the URL to the instance to use the new helper method

Validation Steps Performed

1. Create a crash reporting task
2. Create a notification that uses {{ repro_cmd }}
3. Create a crash report for said task.
4. Note the repro_cmd is updated to include --endpoint for the instance.