Improve progress reporting in the ChunkedStreamManager

Currently there's two small bugs, which have existed around a decade, in the `loaded` property that's sent via the "DocProgress" message from the `ChunkedStreamManager.prototype.onReceiveData` method.

 - When the entire PDF has loaded the `loaded` property can become larger than the `total` property, which obviously doesn't make sense.
   This happens whenever the size of the PDF is *not* a multiple of the `rangeChunkSize` API-option, which is a very common situation.

 - When streaming is being used, the `loaded` property can become smaller than the actually loaded amount of data.
   This happens whenever the size of a streamed chunk is *not* a multiple of the `rangeChunkSize` API-option, which is a common situation.

Author: Snuffleupagus

src/core/chunked_stream.js

@@ -14,7 +14,7 @@
  */
 
 import { arrayBuffersToBytes, MissingDataException } from "./core_utils.js";
-import { assert } from "../shared/util.js";
+import { assert, MathClamp } from "../shared/util.js";
 import { Stream } from "./stream.js";
 
 class ChunkedStream extends Stream {
@@ -511,7 +511,11 @@ class ChunkedStreamManager {
     }
 
     this.msgHandler.send("DocProgress", {
-      loaded: stream.numChunksLoaded * chunkSize,
+      loaded: MathClamp(
+        stream.numChunksLoaded * chunkSize,
+        stream.progressiveDataLength,
+        length
+      ),
       total: length,
     });
   }