Allow setting of pluginNamespace in flexform

[github1maxserv]

Feature Request

Two news lists with pagination on the same page control both paginators at the same time.

A setting in the flexform to change the pluginNamespace would make it possible to make both lists function independently. It's done in EXT:solr but it involves quite a few changes. A challenge will also be to adjust the routing configuration to reflect the pluginNamespace. Solr seems to have a service to handle that.