Understanding the Gendered Impact of COVID-19 on Young Self-Employed Nigerian Women and Coproducing Interventions That Foster Better Systems and Well-Being: Protocol for a Multimethods Study - Iyeyinka Kusi-Mensah; Aarati Taksal; Joshua Akinyemi; Oluwatomisin Owoade; Funmilola M OlaOlorun; Ade F Adeniyi; Olayinka Egbokhare; Olusade Taiwo; Oluwabukola Adeoye; Rita Tamambang; Adeola Afolayan; Chuka Ononye; et al. (JMIR Research Protocols)