feat: update iThenticate EULA version using dateprocess functions

[akshatchhabra]

1. Introduced a function to create submission invitations for iThenticate venues.
2. The submission invitation includes a date-process function that does the following:
   • Check the EULA version in the submission form.
   • Compare it against the current EULA version obtained from iThenticate.
3. If there is a version mismatch:
   • The date-process function posts an invitation edit.
   • This edit is made using the meta invitation.

[carlosmondra]

I would prefer to have something like this:

Suggested change

	if self.iThenticate_plagiarism_check:
	self.invitation_builder.set_iThenticate_submission_invitation()
	else:
	self.invitation_builder.set_submission_invitation()
	self.invitation_builder.set_submission_invitation()
	if self.iThenticate_plagiarism_check:
	self.invitation_builder.set_iThenticate_fields()

That way if the logic in the method invitation_builder.set_submission_invitation() changes, we don't have to change it in two different places. It will also make the logic in self.invitation_builder.set_iThenticate_fields() simpler as we will only need to add the iThenticate fields.