The idea is to insert a span in the text layer with an aria-role set to img
and use the bounding box provided by the attribute field in the tag dict in
order to have non-null dimensions for the image to make it "visible".
In hindsight it occurred to me that there's a couple of smaller issues with this method after it's made asynchronous (in PR 18658).
- If the `render`-method is invoked back-to-back the existing caching doesn't guarantee that re-parsing won't occur, which we can address by introducing a new (private) promise.
- If there's any errors fetching and/or parsing the structTree-data, we'd attempt to parse it again on re-rendering despite that being pointless.
It has been tested with Voice Over (mac) and with NVDA (windows).
When an added stamp annotation is focused, the screen reader will announce
that it's a figure containing a graphic with the added alt-text.
The `Headers` functionality is now available in all browsers/environments that we support, which allows us to consolidate and simplify how the `httpHeaders` API-option is handled; see https://developer.mozilla.org/en-US/docs/Web/API/Headers#browser_compatibility
Also, simplifies the old `NetworkManager`-constructor a little bit.
It was recently brought to my attention that using partial or generated localization ids is bad for maintainability, hence this patch goes through the code-base and replaces any such occurrences.
Currently we repeat virtually the same http/https request code in two different classes in this file, which seems unnecessary and it leads to more code.
With the introduction of Fluent the `getLanguage`-method became synchronous, hence it no longer seems necessary to do the metric-locale check eagerly in the constructor and it can instead be "delayed" until actually needed.
It was recently brought to my attention that using partial or generated localization ids is bad for maintainability, which means that PR 18636 wasn't the correct thing to do.
However, just reverting that one doesn't really fix the problems which is why this patch updates *every* l10n-id in the `PDFDocumentProperties` class (but doesn't touch any `viewer.ftl`-files). Obviously this leads to more verbose code, but that cannot really be helped.
We can remove the `reset`-parameter, since it's redundant, given that it's only used after `PDFDocumentProperties.#reset` has been invoked which means that `this.#fieldData === null` which is equivalent to resetting.
Also, we don't need to have two separate loops in order to update the UI in this method.
Finally, inline the `DEFAULT_FIELD_CONTENT` constant now that it's only used once.
The Node.js url.parse API (https://nodejs.org/api/url.html#urlparseurlstring-parsequerystring-slashesdenotehost)
is deprecated because it's prone to security issues (to the point that Node.js doesn't even publish CVEs for it anymore).
The official reccomendation is to instead use the global URL constructor, available both in Node.js and in browsers.
Node.js filesystem APIs accept URL objects as parameter, so this also avoids a few URL->filepath conversions.
