Dashboard : Should not display the list of sample plugins

[slemeur]

Description

While providing sample plugins is very nice to detail how to use each of the API - we should not be showing that by default to the end users.

When creating a new workspaces / or editing an existing ones, the users will want to configure real plugins only.

When the user is creating a workspaces for Che in Che development or Plugin developemnt, we should be showing those plugins in the samples.

[l0rd]

We should remove the sample plugins from the registry and add them as samples for the che in che stack. Is it right @slemeur?

[slemeur]

Yes sounds good ! thanks @l0rd