(core) Fix test util and upgrade fixtures

Summary:
Fixes a test util that broke after a sync with grist-core, and upgrades
fixtures after a migration was added.

Test Plan: N/A

Reviewers: paulfitz

Reviewed By: paulfitz

Subscribers: paulfitz

Differential Revision: https://phab.getgrist.com/D3810

app/common/themes/GristDark.ts

@@ -366,6 +366,11 @@ export const GristDark: ThemeColors = {
   'menu-toggle-bg': '#32323F',
   'menu-toggle-border': '#A4A4A4',
 
+  /* Info Button */
+  'info-button-fg': '#8F8F8F',
+  'info-button-hover-fg': '#707070',
+  'info-button-active-fg': '#5C5C5C',
+
   /* Button Groups */
   'button-group-fg': '#EFEFEF',
   'button-group-light-fg': '#A4A4A4',

app/common/themes/GristLight.ts

@@ -366,6 +366,11 @@ export const GristLight: ThemeColors = {
   'menu-toggle-bg': 'white',
   'menu-toggle-border': '#929299',
 
+  /* Info Button */
+  'info-button-fg': '#8F8F8F',
+  'info-button-hover-fg': '#707070',
+  'info-button-active-fg': '#5C5C5C',
+
   /* Button Groups */
   'button-group-fg': '#262633',
   'button-group-light-fg': '#929299',