Ability to edit a self guarantor

Reported by Mexina Daniel at https://mifosforge.jira.com/browse/MIFOSX-2814

Original Description:

When a self guarantor has been created there is a chance for a user to attach a wrong saving account or to allocate a wrong amount. For now when that happens you have to delete a guarantor and create again. It will be helpful if a user can edit details of a self guarantor and be able to change deposit account and amount.
You can see this by applying new loan then in the profile of the loan navigate to more -> create guarantor, then create a guarantor (same client) attach the saving account and allocate the amount and submit. Then navigate to more -> view guarantor, there you will be able to see the guarantor with "view" icon, "View transaction", "delete" icon .
It could be better if there was "Edit" icon too.