Fixed position of EuiCodeBlock controls

[cchaos]

I keep noticing that the controls would stay in one location no matter how you changed the paddingSize of the EuiCodeBlock.

Before example:

This PR, adjusts that position based on the padding size.

After example:

Note: The docs change is just temporary to quickly showcase the different examples. I'll revert before merging.

Also,

I beefed up the tests. At the time there was only a single "it renders" test. This adds more for each prop.

Checklist

• Checked in dark mode
• Checked in mobile
• Checked in IE11 and Firefox
• [ ] Props have proper autodocs
• [ ] Added documentation 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

[ryankeairns]

LGTM

[chandlerprall]

Changes LGTM!