Fix / improve HTML table appearance

Working around issues in flutter_html-3.0.0-beta2... But trying to
revert back to 2.2.1 was also not better, there other features aren't
working (e.g. vertical-align:top).
Now at least all tables are displayed correctly

lib/routes/view_page.dart

@@ -65,7 +65,17 @@ class MainHtmlView extends StatelessWidget {
                     style: {
                       "table": Style(
                           // set table width, otherwise they're broken
-                          width: Width(MediaQuery.of(context).size.width - 50))
+                          width: Width(MediaQuery.of(context).size.width - 50)),
+                      "td": Style(
+                          padding: const EdgeInsets.fromLTRB(5, 3, 5, 3)
+                              .htmlPadding),
+                      "th": Style(
+                          textAlign: TextAlign.center,
+                          verticalAlign: VerticalAlign.top),
+// TODO: reduce left padding/margin of <li> items
+// But this doesn't seem to work in flutter_html-3.0.0-beta2
+/*                      "li": Style(
+                          padding: HtmlPaddings.zero, margin: Margins.zero) */
                     },
                     onAnchorTap: (url, _, __) {
                       debugPrint("Link tapped: $url");
@@ -78,26 +88,49 @@ class MainHtmlView extends StatelessWidget {
   }
 }
 
-/// FIXME: Bad workaround for bug in flutter_html 3.0.0-beta2:
+/// FIXME: workarounds for bugs in flutter_html 3.0.0-beta2:
 /// https://github.com/Sub6Resources/flutter_html/issues/1188
-/// Remove all <ul> and <p> in table cells.
-/// That means some content isn't displayed! But that's still better than
-/// a completely unusable app (turns completely white) when clicking
-/// on some worksheets like "Training Meeting Outline" and "Hearing from God"
+/// Get rid of <ul> and <p> in table cells to avoid completely unusable app
+/// and fix some other issues
 ///
-/// Hopefully flutter_html 3.0.0 is soon released and fixes the issue
+/// Hopefully flutter_html 3.0.0 is soon released and fixes the issues
 sanitize(String html) {
   var dom = parse(html);
-//  debugPrint("Number of p in td: ${dom.querySelectorAll('td p').length}");
 
+  // Change <td><p>Content</p></td> to <td>Content</td>
+  // FIXME: That could actually be fixed in the HTML generated by pywikitools
   for (var element in dom.querySelectorAll('td p')) {
-    debugPrint('Warning: Removing <p> element in <td> as workaround for a bug');
+    debugPrint('Warning: Found <p> element in <td>, removing...');
+    element.parent!.innerHtml = element.innerHtml;
     element.remove();
   }
+  // Change <th><p>Content</p></th> to <th>Content</th>
+  // FIXME: That could actually be fixed in the HTML generated by pywikitools
+  for (var element in dom.querySelectorAll('th p')) {
+    debugPrint('Warning: Found <p> element in <th>, removing...');
+    element.parent!.innerHtml = element.innerHtml;
+    element.remove();
+  }
+  // e.g. Hearing_from_God:
+  // Change <td><ul><li>item1</li><li>item2</li></ul></td> to
+  // <td>• item1<br/>• item2<br/></td>
+  // FIXME: Remove once the issue 1188 (see above) is solved
   for (var element in dom.querySelectorAll('td ul')) {
-    debugPrint(
-        'Warning: Removing <ul> element in <td> as workaround for a bug');
+    debugPrint('Warning: Found <ul> element in <td>: Working around the bug');
+    String newHtml = '';
+    for (var li in element.children) {
+      assert(li.localName == 'li');
+      newHtml += '• ${li.innerHtml}<br/>';
+    }
+    element.parent!.innerHtml = newHtml;
     element.remove();
   }
+  // e.g. "Three different voices" in Hearing_from_God or Time_with_God
+  // has <th style="width:x%"> which confuses flutter_html, so remove
+  // the style attribute
+  for (var element in dom.querySelectorAll('th')) {
+    element.attributes.remove('style');
+  }
+
   return dom;
 }