Implement Support for multiple series from a dataframe

[bianchidotdev]

References to other Issues or PRs

Brief description of what is fixed or changed

Allows the plotting of multiple series on a highcharts plot along a single index. Reasonable support for Date-based indexes as well as the Daru::DateTimeIndex.

Testcase / documentation

Existing tests were modified to show the new behavior. Unfortunately, this breaks the existing API for HighCharts Map. I'm not sure the correct path forward, but I'm wagering this PR will not be able to be merged until we figure out a better way to support the different data structure needs for the different chart types.

Other comments

Added in TODO comments on broken tests.

Rubocop seems broken already at this time from files I didn't touch. The Highcharts::Adapter.init method is breaking method length and complexity, but since it breaks Highchart Maps and the whole thing would need to be restructured, I'm not going to prematurely optimize that.

Let me know if you're interested in working through a solution that will work for highcharts map as well as multiple series support. Otherwise, I'll just use my fork for my financial analysis work.

[shekhar-rajak]

Hi, Any update?

[bianchidotdev]

Closing as I no longer use this and I never got it to the point where it could be merged.