Upgrading TypeScript to 3.7.2

[anishagg17]

Summary

Closes #3292

Checklist

- [ ] Check against all themes for compatibility in both light and dark modes
- [ ] 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

[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?

[anishagg17]

this line is not ignored even // @ts-ignore-next-line is used

[anishagg17]

This is the second breaking Change caused, rest all have been fixed

[chandlerprall]

data_grid.test.tsx

Needs a second ignore comment,

      // @ts-ignore-next-line
      columnSorter
        .find('EuiSwitch')
        .props()
        // @ts-ignore-next-line
        .onChange();

observer.ts

Looks like it's an issue with changes to @types/react -

        // React.Props<T> is now deprecated, which means that the `children`
        // property is not available on `P` by default, even though you can
        // always pass children as variadic arguments to `createElement`.
        // In the future, if we can define its call signature conditionally
        // on the existence of `children` in `P`, then we should remove this.
        readonly props: Readonly<P> & Readonly<{ children?: ReactNode }>;

but can be fixed in the EUI component with:

    const props: BaseProps = this.props;
    return props.children(this.updateChildNode);

package.json

devDependencies can both be updated too

    "@types/react": "^16.9.34",
    "@types/react-dom": "^16.9.6",

yarn.lock

Changing the above dependencies will create an issue with yarn which needs a manual resolution:

• find the "@types/react@*": and "@types/react@^16.9.23": entries in yarn.lock and delete them
• re-run yarn
• commit the resulting yarn.lock

CHANGELOG.md

Needs a breaking change entry

[chandlerprall]

Merged master into this branch to get the changelog entry into the right location, as we released an EUI version yesterday. I also removed the react & react-dom mentions in the changelog as those changes only affect the devDependencies and not any published version.

jenkins test this

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_3295/

[chandlerprall]

Jest OOMed. jenkins test this

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_3295/