Prevent NPE in CSV diff rendering when column removed (#17018) (#17377)

Backport of #17018

Fixes #16837 if a column is deleted.

web_src/less/_base.less

@@ -76,8 +76,10 @@
   --color-diff-removed-word-bg: #fdb8c0;
   --color-diff-added-word-bg: #acf2bd;
   --color-diff-removed-row-bg: #ffeef0;
+  --color-diff-moved-row-bg: #f1f8d1;
   --color-diff-added-row-bg: #e6ffed;
   --color-diff-removed-row-border: #f1c0c0;
+  --color-diff-moved-row-border: #d0e27f;
   --color-diff-added-row-border: #e6ffed;
   --color-diff-inactive: #f2f2f2;
   /* target-based colors */

web_src/less/_repository.less

@@ -1500,6 +1500,12 @@
       background-color: var(--color-diff-removed-row-bg) !important;
     }
 
+    td.moved,
+    th.moved,
+    tr.moved {
+      background-color: var(--color-diff-moved-row-bg) !important;
+    }
+
     tbody.section {
       border-top: 2px solid var(--color-secondary);
     }

web_src/less/themes/theme-arc-green.less

@@ -71,8 +71,10 @@
   --color-diff-removed-word-bg: #6f3333;
   --color-diff-added-word-bg: #3c653c;
   --color-diff-removed-row-bg: #3c2626;
+  --color-diff-moved-row-bg: #818044;
   --color-diff-added-row-bg: #283e2d;
   --color-diff-removed-row-border: #634343;
+  --color-diff-moved-row-border: #bcca6f;
   --color-diff-added-row-border: #314a37;
   --color-diff-inactive: #353846;
   /* target-based colors */