By Lenn Thompson, Executive Editor Long Island rose is a beautiful thing.. beautiful in its insane diversity. From sweet to dry and every residual sugar level in between the East End of Long Island has you covered. But the diversity doesn't stop there. Just about any red wine variety grown here ends up as rose, including the usual suspects like merlot, cabernet sauvignon and pinot noir as well as grapes like refosco and cabernet franc. Blending is common and not reserved for red grapes. Some of the region's best-loved roses are blends of red varieties with large percentages of…