JSON format in alert body is unintentionally escaped and broken when using alert template macro

[takanau]

Issue Summary

When using alert template macro (ex: {{QUERY_RESULT_ROWS}}, cf) in alert body, the result is HTML escaped and its JSON format is broken like this:

[{'column': 1}]

Steps to Reproduce

• https://github.com/getredash/redash/blob/master/redash/models/__init__.py#L1039
• https://github.com/getredash/redash/blob/master/redash/utils/__init__.py#L139-L141

When rendering alert template, mustache_render should be used, not mustache_render_escape.

Technical details:

• Redash Version: 24.12.0-dev

I guess this problem caused by #5996 (Version: 23.09.0)

[perceptron01]

I'm also encountering this issue when trying to send alert messages to Slack.
This appears to be related to the issue reported in #7362

[webdevian]

Not sure if this is useful to either of you, but I have found that in the template you can iterate the QUERY_RESULT_ROWS array to get individual values out and format them however you want. It doesn't show up some data types in the in the preview, but they do come through to slack in the alert

{{#QUERY_RESULT_ROWS}}{{latest_order}}{{/QUERY_RESULT_ROWS}}