Refactor wikicharts code to clean up functions and function names
-Renamed multi_yoy_annotate to multi_annotate because it is not restricted to just performing yoy calc. -Renamed calc_yoy and calc_mom to create_yoy_annotation and calc_mom_annotation to reflect that these functions both calculate and generate the annotation. -Removed references to yoy_note in chart code and wikicharts because annotate and multi_annotate can be used instead and will be more consistent with other charts that have annotations. -Removed bottom annotation and associated code from charts
Edited by Hghani