move urlparams mixin into a function for less code and makes it easier to add/remove custom parameters.
move urlparams mixin into a function for less code and makes it easier to add/remove custom parameters.

Esri/application-boilerplate-js,Ricardh522/application-boilerplate-js,brudo/application-boilerplate-js,shekhawatravi/application-boilerplate-js,Esri/application-boilerplate-js,shekhawatravi/application-boilerplate-js,brudo/application-boilerplate-js,Ricardh522/application-boilerplate-js