Improve formatting of Jinja blocks

[UnknownPlatypus]

Given this:

<p>
{% if alert_level == "low" %} the sky condition{% elif alert_level == "storm" %} the Storm warning{% else %} the Heatwave alert{% endif %}
</p>

It was previously getting formatted to this:

<p>
    {% if alert_level == "low" %}
        the sky condition{% elif alert_level == "storm" %}
        the Storm warning{% else %}
        the Heatwave alert{% endif %}
</p>

And will now respect the whitespace sensitivity of the parent node (the p tag here) and be formatted like so:

<p>
    {% if alert_level == "low" %}
        the sky condition
    {% elif alert_level == "storm" %}
        the Storm warning
    {% else %}
        the Heatwave alert
    {% endif %}
</p>

I think it make sense because jinja block/tags basically disapear when rendered.

Test cases come from real world exemple were the formatting was weird previously.
You can see the before in this commit, and the after in the last commit

[netlify]

✅ Deploy Preview for markup-fmt ready!

Name	Link
🔨 Latest commit	20af8b3
🔍 Latest deploy log	https://app.netlify.com/projects/markup-fmt/deploys/69c300488eee30000825339d
😎 Deploy Preview	https://deploy-preview-205--markup-fmt.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[UnknownPlatypus]

@g-plane I found an interesting case where this is unsafe to apply the current changes, jinja trans block

-            {% trans %}Your server has exceeded the limit for how often this action can be performed.{% endtrans %}
+            {% trans %}
+                Your server has exceeded the limit for how often this action can be performed.
+            {% endtrans %}

How can we manage to have the information about the parent jinja tag inside format_control_structure_block_children, it's seems we only know about the parent html node ?

Finding other edge cases that make me think this is much more involved than I thought. For exemple this change would be incorrect too I think:

             _('Organization URL')
         }}</label>
         <div id="id_realm_subdomain" class="not-editable-realm-field">
-            {% if form.realm_subdomain.value() %}{{ form.realm_subdomain.value() }}.{%
-                endif
-            %}{{ external_host }}
+            {% if form.realm_subdomain.value() %}
+                {{ form.realm_subdomain.value() }}.
+            {% endif %}{{ external_host }}
         </div>
     </div>
 </div>

[g-plane]

We can limit the behavior of inserting line breaks to a set of known tags, but don't do this check in format_control_structure_block_children.

[UnknownPlatypus]

but don't do this check in format_control_structure_block_children.

We should do it in the doc implementation of JinjaTag then ?

[g-plane]

Maybe in JinjaBlock?