The path to dialog I am providing is '/etc/workflow/dialogs/DateTimePicker'. As per the error, I assume that I need to have touchUiDialogPath somewhere in the new DateTimePicker component. If yes, where should I add and what should be the value for the touchUiDialogPath? I want to provide datepicker from granite/ui/components/coral/foundation/form/datepicker. If I directly add 'granite/ui/components/coral/foundation/form/datepicker' path in dialog path of the dynamic participant step, I see same error.
We should locate the cq:dialog node to the dialog path property. In this case, add "/etc/workflow/dialogs/DateTimePicker/cq:dialog" which should help solve the issue.
Regarding other related queries,
In order to have a segregation of code from OOB paths (/libs, /etc) , we can create within /apps
Something like "/apps/your project/workflow/dialogs/any meaningful name/cq:dialog"
OOB datepicker resource (/libs/granite/ui/components/coral/foundation/form/datepicker) holds the logic responsible for rendering date picker. In particular it has <coral-datepicker> to render the picker widget and its related attributes.
It will not have dialog. Instead, it is used for creating and hence rendering dialog fields