materials Review All-in-One Gel-Based Electrochromic Devices: Strengths and Recent Developments Yolanda Alesanco ID , Ana Viñuales *, Javier Rodriguez and Ramón Tena-Zaera CIDETEC, Paseo Miramón, 196, 20014 Donostia-San Sebastian, Spain; yalesanco@cidetec.es (Y.A.); jrodriguez@cidetec....