Renamed euiPaletteNegtive and euiPalettePositive

[hetanthakkar]

Summary

Fixes issue #4766

Checklist

• Check against all themes for compatibility in both light and dark modes
• Checked in mobile
• Checked in Chrome, Safari, Edge, and Firefox
• Props have proper autodocs and **[playground toggles](https://github.com/elastic/eui/blob/master/wiki/documentation-guidelines.md#adding-playground-toggles)**
• Added documentation
• Checked Code Sandbox works for the any docs examples
• Added or updated jest tests
• Checked for breaking changes and labeled appropriately
• Checked for accessibility including keyboard-only and screenreader modes
• A changelog entry exists and is marked appropriately

[kibanamachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[hetanthakkar]

@miukimiu I just renamed the euiPaletteNegtive and euiPalettePositive! Is my approach correct!?

[hetanthakkar]

@thompsongl What does this label mean!

[cchaos]

@hetanthakkar1 We really appreciate your enthusiasm to help us out here, but I'm going to close this PR as it is a MAJOR breaking change and that issue is still under discussion (see the applied github labels). I'd stick to issues with the good-first-issue label as those should have well defined actions.

[cchaos]

A breaking change means that all consumers who were using the euiPaletteNegative named exports would break their implementation with this name change. It's something we need to heavily consider as it impacts a lot of usages of EUI.

[hetanthakkar]

@cchaos Got it thanks! Yeh this need serious attention!