By Estelle Shirbon JERUSALEM (Reuters) – On Israeli city streets and on television, in shops and in cafes, one symbol of solidarity with hostages held in Gaza has become ubiquitous in the 100 days since Hamas abducted them: military-style dog tags worn on neckchains. The small metal rectangles, similar to those soldiers carry for identification, are typically inscribed with two slogans in Hebrew, “our hearts are held hostage in Gaza” and “together we will win”, and one in English, “bring them home now”. “Everyone wants to show their support one way or another,” said Shayna Roth, 36, a digital …