Adding Negative Functionallity to MapChartComponent

[mmehta2669]

Description

This changing the negative Functionality in the MapChartComponent. It does this bey changing the scaling to factor in the max-min, and adds and minShift that shifts the negative values into the positive with maintaining that the radius decreases as the absolute value of the negative meter increases

Fixes [#1205]

(In general, OED likes to have at least one issue associated with each pull request. Replace [issue] with the OED GitHub issue number. In the preview you will see an issue description if you hover over that number. You can create one yourself before doing this pull request. This is where details are normally given on what is being addressed. Note you should not use the word "Fixes" if it does not completely address the issue since the issue would automatically be closed on merging the pull request. In that case use "Partly Addresses #[issue].)

Type of change

(Check the ones that apply by placing an "x" instead of the space in the [ ] so it becomes [x])

• [ ] Note merging this changes the database configuration.
• [ ] This change requires a documentation update

Checklist

(Note what you have done by placing an "x" instead of the space in the [ ] so it becomes [x]. It is hoped you do all of them.)

• [x] I have followed the OED pull request ideas
• [x] I have removed text in ( ) from the issue request
• [x] You acknowledge that every person contributing to this work has signed the OED Contributing License Agreement and each author is listed in the Description section.

Limitations

I think that the color change for the negative meters could be more dynamic, however that may require a more refined color selection function

[mmehta2669]

Fixes #1205

[lawsj]

I see in the code that you added the various min functions to help set the size and scale of the circles that appear on the maps. This addition allows the user to have a more clear indication when a negative value is reported. Good job!