FramesCollection -- use FrameConnotationProvider instead

[nicolay-r]

Reason: the common method required from FramesCollection is a try_get_frame_polarity. The latter is related to frame connotations, where sentiment connotation is a one of many other types of possible (potential) connotations.
Related to #118

In further:

• sentiment connotation is a particular type (class);
• connotations might be schema;