Use the ESLint no-restricted-syntax rule to ensure that assert is always called with two arguments

Having `assert` calls without a message string isn't very helpful when debugging, and it turns out that it's easy enough to make use of ESLint to enforce better `assert` call-sites.
In a couple of cases the `assert` calls were changed to "regular" throwing of errors instead, since that seemed more appropriate.

Please find additional details about the ESLint rule at https://eslint.org/docs/rules/no-restricted-syntax

src/core/document.js

@@ -767,7 +767,15 @@ class PDFDocument {
 
   _getLinearizationPage(pageIndex) {
     const { catalog, linearization } = this;
-    assert(linearization && linearization.pageFirst === pageIndex);
+    if (
+      typeof PDFJSDev === "undefined" ||
+      PDFJSDev.test("!PRODUCTION || TESTING")
+    ) {
+      assert(
+        linearization && linearization.pageFirst === pageIndex,
+        "_getLinearizationPage - invalid pageIndex argument."
+      );
+    }
 
     const ref = Ref.get(linearization.objectNumberFirst, 0);
     return this.xref

src/core/obj.js

@@ -578,7 +578,11 @@ class Catalog {
             }
             break;
           default:
-            assert(typeof value === "boolean");
+            if (typeof value !== "boolean") {
+              throw new FormatError(
+                `viewerPreferences - expected a boolean value for: ${key}`
+              );
+            }
             prefValue = value;
         }
 

src/core/parser.js

@@ -216,7 +216,7 @@ class Parser {
       } else if (state === 1) {
         state = ch === I ? 2 : 0;
       } else {
-        assert(state === 2);
+        assert(state === 2, "findDefaultInlineStreamEnd - invalid state.");
         if (ch === SPACE || ch === LF || ch === CR) {
           maybeEIPos = stream.pos;
           // Let's check that the next `n` bytes are ASCII... just to be sure.

src/core/worker_stream.js

@@ -26,7 +26,10 @@ class PDFWorkerStream {
   }
 
   getFullReader() {
-    assert(!this._fullRequestReader);
+    assert(
+      !this._fullRequestReader,
+      "PDFWorkerStream.getFullReader can only be called once."
+    );
     this._fullRequestReader = new PDFWorkerStreamReader(this._msgHandler);
     return this._fullRequestReader;
   }