Ensure that we fully load Type3 fonts in PartialEvaluator.getTextContent

This is necessary now, since with the previous patch the /FontBBox potentially depends on the contents of the /CharProcs-streams.
Note that if `getOperatorList` is called *before* `getTextContent`, this patch doesn't matter since the font is already fully loaded/parsed. However, for e.g. the `text` test-cases this is necessary to ensure correct reference images.

src/core/evaluator.js

@@ -2251,6 +2251,20 @@ class PartialEvaluator {
     function handleSetFont(fontName, fontRef) {
       return self
         .loadFont(fontName, fontRef, resources)
+        .then(function (translated) {
+          if (!translated.font.isType3Font) {
+            return translated;
+          }
+          return translated
+            .loadType3Data(self, resources, task)
+            .catch(function () {
+              // Ignore Type3-parsing errors, since we only use `loadType3Data`
+              // here to ensure that we'll always obtain a useful /FontBBox.
+            })
+            .then(function () {
+              return translated;
+            });
+        })
         .then(function (translated) {
           textState.font = translated.font;
           textState.fontMatrix =