feat(cockpit): add view switcher to definition and instance views

Plugins may register views for process definition and instance via
the key <cockpit.(processDefinition|processInstance).view>.

Registered plugins will be shown as a pill which may be clicked to
switch the view.

BREAKING CHANGE:

renamed entry points
- cockpit.(processDefinition|processInstance).action ->
cockpit.(processDefinition|processInstance).live.action

- cockpit.(processDefinition|processInstance).view ->
cockpit.(processDefinition|processInstance).live.tab

Closes CAM-1649
fix(cockpit/dev-setup): rename test process definition id