align shinydashboard tab data-value with shiny tabs

[carlganz]

I guess you'd probably want to update the codebase to use bslib, but since that is a lot of work updating shiny dashboard tabs to include a data-value will allow other shiny related packages (like mine) to work with tabs across shiny and shiny dashboard in a generic way (see https://github.com/carlganz/rintrojs/blob/master/inst/javascript/rintro.js#L48)

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[YongbingDing]

您好，丁永兵已经收到您的邮件，谢谢。