Remove GUI to create ISA-compliant Templates from scratch

[floradanna]

Remove GUI to create ISA-compliant Templates from scratch.
User of GUI can only create ISA-compliant Templates starting from existing ISA-compliant Templates.

[kdp-cloud]

At the start of creating a new template, the 'Add new attribute' button is hidden, preventing the user from creating a template from scratch.

Applying an existing template, reveals the button again. Users can add new template attributes if they want to!

When editing an existing template, the button is also shown as well.