feat(web): rewrite frontend worker handling

This completely rewrites how the proof of work challenge works based on
feedback from browser engine developers and starts the process of making
the proof of work function easier to change out.

- Import @aws-crypto/sha256-js to use in Firefox as its implementation
  of WebCrypto doesn't jump directly from highly optimized browser
  internals to JIT-ed JavaScript like Chrome's seems to.
- Move the worker code to `web/js/worker/*` with each worker named after
  the hashing method and hash method implementation it uses.
- Update bench.mjs to import algorithms the new way.
- Delete video.mjs, it was part of a legacy experiment that I never had
  time to finish.
- Update LibreJS comment to add info about the use of
  @aws-crypto/sha256-js.
- Also update my email to my @techaro.lol address.

Signed-off-by: Xe Iaso <me@xeiaso.net>

web/build.sh

@@ -28,6 +28,9 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 
+Includes code from https://github.com/aws/aws-sdk-js-crypto-helpers which is
+used under the terms of the Apache 2 license.
+
 @licend  The above is the entire license notice
 for the JavaScript code in this page.
 */'