After the changes in PR #14428, the [`normalizeWhitespace` option](https://github.com/mozilla/pdf.js/blob/1087b4dffdf5884ad17669fda54c59dd810667d3/src/display/api.js#L1072-L1073) is now in most (or perhaps even all) cases being ignored and treated as if `normalizeWhitespace = true` is passed to the `PDFPageProxy.{getTextContent, streamTextContent}` methods.[1]

With the changes in PR #14428 we're now handling all whitespaces *consistently* in the `PartialEvaluator.getTextContent` method, which together with other (somewhat) recent improvements have fixed many textLayer issues by handling both coalescing of repeated spaces and proper space insertion between text chunks.
Looking briefly at this code, it seems to me that trying to re-instate "proper" `normalizeWhitespace = false` handling would be quite difficult and would likely hurt readability (assuming it's even at all possible now).
Furthermore, note that in both the viewer and the browser-tests we're only ever using `normalizeWhitespace = true` which means that the other code-path isn't really used all that much.

All-in-all, I'd probably suggest that we simply remove the `normalizeWhitespace` option and make the relevant methods always carry out the normalization since that's what e.g. the viewer uses.

Any thoughts/opinions about this?
/cc @timvandermeij 
/cc @calixteman 

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[1] One example is the `issue6612.pdf` document in the test-suite, added together with the option, where "regular" spaces are now being returned regardless of the `normalizeWhitespace` value.
*   into. Defaults to the current document.
 * @property {boolean} [disableRange] - Disable range request loading of PDF
 *   files. When enabled, and if the server supports partial content requests,
 *   then the PDF will be fetched in chunks. The default value is `false`.
 * @property {boolean} [disableStream] - Disable streaming of PDF file data.
 *   By default PDF.js attempts to load PDF files in chunks. The default value
 *   is `false`.
 * @property {boolean} [disableAutoFetch] - Disable pre-fetching of PDF file
 *   data. When range requests are enabled PDF.js will automatically keep
 *   fetching more data even if it isn't needed to display the current page.
 *   The default value is `false`.
 *
 *   NOTE: It is also necessary to disable streaming, see above, in order for
 *   disabling of pre-fetching to work correctly.
 * @property {boolean} [pdfBug] - Enables special hooks for debugging PDF.js
 *   (see `web/debugger.js`). The default value is `false`.
 */
/**
 * This is the main entry point for loading a PDF and interacting with it.
 *
 * NOTE: If a URL is used to fetch the PDF data a standard Fetch API call (or
 * XHR as fallback) is used, which means it must follow same origin rules,
 * e.g. no cross-domain requests without CORS.
 *
 * @param {string|URL|TypedArray|PDFDataRangeTransport|DocumentInitParameters}
 *   src - Can be a URL where a PDF file is located, a typed array (Uint8Array)
 *         already populated with data, or a parameter object.
 * @returns {PDFDocumentLoadingTask}
 */
function getDocument(src) {