Provide rights to admin for changing constant values

[himanshuvarandani]

Prerequisite Issue #146

Constants will be transferred to database in Issue #146 and needs to be updated continuously, so rights can be provided to admin or any specific role to change variables.

Solution is to create forms for each constant list and update database with the data provided by admin.

[pnijhara]

Yes, you can do this on the admin portal.