Rework `Views` and `Clones` (#3168)

Makes `Repository.get_views_traffic` and `Repository.get_clones_traffic`
return `View` and `Clones`, respectively, instead of `dict`s. Classes
`View` and ` Clones` were identical, their purpose is not implemented by
a single class `Traffic`. Classes `View` and ` Clones` now represent the
full view and clones response returned by the API, where `list[Traffic]`
is only one element of.