`.to_html()` method produces incorrectly formatted `<div>` element string for `full_html=False` option

[tallamjr]

When one invokes plotly.io.to_html(fig, include_plotlyjs=False, full_html=False) the following
example output is produced:

'<div>\n        \n        \n            <div id="8a9f01d7-9e37-401b-a602-15b3bbdac943"
class="plotly-graph-div" style="height:100%; width:100%;"></div>\n            <script
type="text/javascript">\n                \n                    window.PLOTLYENV=window.PLOTLYENV ||
{};\n                    \n                if
(document.getElementById("8a9f01d7-9e37-401b-a602-15b3bbdac943")) {\n
Plotly.newPlot(\n                        \'8a9f01d7-9e37-401b-a602-15b3bbdac943\',\n
...

Note the \n characters as well as a single quoted id.

The resulting <div> element appears like this when placed in a markdown document, i.e no plot
showing up:

Note I have ensured to include:

<script src="https://cdn.plot.ly/plotly-latest.min.js"></script>

above the <div> element.

Removing the \n characters and replacing the single quoted id with double quotes seems to
resolve this issue.

See PR #2469