[docs] Increased support for TS types -> props table/docgen

[chandlerprall]

Summary

This started by looking at why EuiPopoverPanelProps were not showing in the props table in #5977. Turns out the code for TS->docgen was limited to a very specific type def. This PR adds support for basic types and a fallback to use whatever TS gives us in other cases.

It doesn't solve EuiPopoverPanelProps in a great way,

but at least it shows up now and aligns with how other complex types are displayed. The basic type handling does include meaningful details,

type FooProps = {
  foo: string;
  bar?: number;
}

Checklist

- [ ] Checked in both light and dark modes
- [ ] Checked in mobile
- [ ] Checked in Chrome, Safari, Edge, and Firefox

• Props have proper autodocs and playground toggles
  - [ ] Added documentation
  - [ ] Checked Code Sandbox works for any docs examples
  - [ ] Added or updated jest and cypress tests
  - [ ] Checked for breaking changes and labeled appropriately
  - [ ] Checked for accessibility including keyboard-only and screenreader modes
  - [ ] Updated the Figma library counterpart
  - [ ] A changelog entry exists and is marked appropriately

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_6000/

[thompsongl]

Awesome! Tested locally with a few different type and interface shapes