Files view: drop the ASCII column from the change-details hex views

- the modal's hex views carried a 16-byte ASCII column per row; file data is
  rarely text and the column halved the room for the two before/after views,
  so it is gone: `hexImageRows` no longer builds an `ascii` field,
  `hexImageHtml` no longer emits it and the `.hex-ascii` CSS rule is removed
- tests: the hex-row test asserts the field is gone (so it cannot come back
  silently); README/README_RUS wording updated
- SW cache simtrace-analyser-v67 (cosmetic, no version bump)

frontend/tests/comprion.test.js

@@ -313,8 +313,8 @@ test('Files view: the hex image rows mark changed, new and unknown bytes', () =>
 	assert.deepEqual(cells[2], {hex: '43', cls: 'hex-changed'});
 	assert.deepEqual(cells[4], {hex: '--', cls: 'hex-unknown'});   // the gap
 	assert.deepEqual(cells[8], {hex: '65', cls: 'hex-new'});
-	// ASCII column: printable bytes stay, gaps and the unobserved tail are blank.
-	assert.equal(view.rows[0].ascii, 'ABCD    ef      ');
+	// No ASCII column any more (it wasted the modal's width).
+	assert.equal(view.rows[0].ascii, undefined);
 });
 
 test('Files view: the hex image respects the row limit', () => {