By Sarah Wu and Yimou Lee TAIPEI (Reuters) -Taiwan President Tsai Ing-wen resigned as head of the ruling Democratic Progressive Party (DPP) on Saturday after her strategy to frame local elections as showing defiance to China’s rising bellicosity failed to pay off and win public support. The elections for mayors, county chiefs and local councillors are ostensibly about domestic issues such as the COVID-19 pandemic and crime, and those elected will not have a direct say on China policy. But Tsai had recast the election as being more than a local vote, saying the world is watching how Taiwan defe…