fix(callouts): prevent newline after obsidian callouts title

[saberzero1]

Closes #1020

This change has the nice added benefit of more closely following Obsidian's callouts specification while not affecting GitHub's Alert Markdown.

Test set used:

---
title: test callouts
---

```markdown
> [!NOTE]
> Useful information that users should know, even when skimming content.

> [!TIP]
> Helpful advice for doing things better or more easily.

> [!IMPORTANT]
> Key information users need to know to achieve their goal.

> [!WARNING]
> Urgent info that needs immediate user attention to avoid problems.

> [!CAUTION]
> Advises about risks or negative outcomes of certain actions.
```

```md
> [!NOTE]
> Useful information that users should know, even when skimming content.

> [!TIP]
> Helpful advice for doing things better or more easily.

> [!IMPORTANT]
> Key information users need to know to achieve their goal.

> [!WARNING]
> Urgent info that needs immediate user attention to avoid problems.

> [!CAUTION]
> Advises about risks or negative outcomes of certain actions.
```

> [!NOTE]
> Useful information that users should know, even when skimming content.

> [!TIP]
> Helpful advice for doing things better or more easily.

> [!IMPORTANT]
> Key information users need to know to achieve their goal.

> [!WARNING]
> Urgent info that needs immediate user attention to avoid problems.

> [!CAUTION]
> Advises about risks or negative outcomes of certain actions.

[jackyzha0]

can you also test this with custom titles?

> [!NOTE] test title
> Useful information that users should know, even when skimming content.

we originally added this transform to handle this case

[saberzero1]

can you also test this with custom titles?

> [!NOTE] test title
> Useful information that users should know, even when skimming content.

we originally added this transform to handle this case

> [!NOTE] with a title
> This note has a title.

Results in:

<blockquote class="callout note" data-callout="note">
  <div class="callout-title">
    <div class="callout-icon"></div>
    <div class="callout-title-inner">
      <p>with a title </p>
    </div>

  </div>
  <p>This note has a title.</p>
</blockquote>

Which looks like:

[jackyzha0]

sorry one more test for my sanity :)

> [!NOTE] with a title _and_ **formatting**
> This note has a title. yay

[saberzero1]

sorry one more test for my sanity :)

> [!NOTE] with a title _and_ **formatting**
> This note has a title. yay

Alright, one second.

EDIT:

<blockquote class="callout note" data-callout="note">
  <div class="callout-title">
    <div class="callout-icon"></div>
    <div class="callout-title-inner">
      <p>with a title <em>and</em> <strong>formatting</strong>
        This note has a title. yay</p>
    </div>

  </div>
</blockquote>

Changing the markdown to:

> [!NOTE] with a title _and_ **formatting**
>
> This note has a title. yay

Fixes that issue (this is basically the old behavior).

I'll look into a fix shortly.

[saberzero1]

I'll need some more time to implement an elegant fix.

Currently we check for newline \n characters in text value to split the title, but emphasis, strong, etc., type have children with a text value, instead of a text value themselves.

I'll let you know when I have properly addressed this. @jackyzha0

[aarnphm]

Let's also include this in #1496