Ignore no-unused-vars in .api, organize all remaining imports

addons/xterm-addon-serialize/test/SerializeAddon.api.ts

@@ -204,7 +204,6 @@ describe('SerializeAddon', () => {
       sgr(NO_INVISIBLE) + line,
       sgr(NO_STRIKETHROUGH) + line
     ];
-    const rows = lines.length;
     await writeSync(page, lines.join('\\r\\n'));
     assert.equal(await page.evaluate(`serializeAddon.serialize();`), lines.join('\r\n'));
   });
@@ -593,7 +592,6 @@ const FG_RGB_GREEN = '38;2;0;255;0';
 const FG_RGB_YELLOW = '38;2;255;255;0';
 const FG_RESET = '39';
 
-
 const BG_P16_RED = '41';
 const BG_P16_GREEN = '42';
 const BG_P16_YELLOW = '43';