[cleanup] Remove ResourceType from ContentData class

We only required it to determine if a ContentData is textual content
or not. The MIME type conveys the same information. To this end this
CL introduces a hard-coded list of MIME types that have textual content
besides "text/*".

This is somewhat cleaner, as ContentData now bundles the minimal
information to pass around bytes in the frontend: The raw data,
the mime type and a character encoding.

[email protected]

Bug: 1509336
Change-Id: I70061a263c0a18ebc7c435bdb611164ec9363e84
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/5210350
Reviewed-by: Wolfgang Beyer <[email protected]>
Commit-Queue: Simon Zünd <[email protected]>
diff --git a/front_end/panels/network/NetworkLogView.ts b/front_end/panels/network/NetworkLogView.ts
index fbc435e..4cee999 100644
--- a/front_end/panels/network/NetworkLogView.ts
+++ b/front_end/panels/network/NetworkLogView.ts
@@ -870,7 +870,7 @@
     let content: string;
     if (SDK.ContentData.ContentData.isError(contentData)) {
       content = '';
-    } else if (!contentData.resourceType.isTextType()) {
+    } else if (!contentData.isTextContent) {
       content = contentData.asDataUrl() ?? '';
     } else {
       content = contentData.text;