removing empty text nodes

[pkra]

Some valid JATS constructs can cause Lens to add empty text nodes (and maybe other types of nodes as well?).

For example,

<p><disp-formula>...</disp-formula></p>`

can lead to something like

<div class="content-node paragraph" data-id="paragraph_1">
    <div class="content">
        <div class="content-node text" data-id="text_1">
            <div class="content">
            </div>
            <div class="focus-handle"></div>
        </div>
    </div>
    <div class="focus-handle"></div>
</div>
<div class="content-node formula" data-id="formula_1">
    <div class="focus-handle"></div>
    <div class="content">
    ...
    </div>
</div>

which produces a sizable gap in the document due to the empty .paragraph subtree.

It would be great if Lens could check if a node has content before injecting it. It seems like a well-placed check for length 0 should be enough, but I have trouble finding the right spot for it.