Add label for `label=0` kwarg (#2837)
Add label for `label=0` kwarg (#2837)

* Add label for `label=0` kwarg

* Fix ambiguous comparision of label with 0

* Add methods for handling plot labels

* Remove type annotations for series indexes

* Replace label conversion code with shorter version

* Handel symbol args for labels in more consistent manner

* Broadcast label_to_string to handle Array of labels

Co-authored-by: Simon Christ <eef8d6511eaabaa6bd3cac1b767e0784d09ce59b@gmx.de>

Co-authored-by: Simon Christ <eef8d6511eaabaa6bd3cac1b767e0784d09ce59b@gmx.de>
tbreloff/Plots.jl