Use JSON.parse for parsing teambuilder tables (smogon#1714)

This optimizes JavaScript parsing performance. V8 developers
recommend applying this optimization for objects of 10 kB or
larger, see <https://v8.dev/blog/cost-of-javascript-2019#json>
for more details. Teambuilder tables are 3.5 MBs which is much
more than 10 kB.

build-tools/build-indexes

@@ -1018,7 +1018,7 @@ process.stdout.write("Building `data/teambuilder-tables.js`... ");
 		}
 	}
 
-	buf += 'exports.BattleTeambuilderTable = ' + JSON.stringify(BattleTeambuilderTable) + ';\n\n';
+	buf += `exports.BattleTeambuilderTable = JSON.parse('${JSON.stringify(BattleTeambuilderTable).replace(/['\\]/g, "\\$&")}');\n\n`;
 
 	fs.writeFileSync('data/teambuilder-tables.js', buf);
 }