docs: Bring in polyfills for IE11 📚

fix: Guard against accessing null ref with inline search input (dowjo…

…nes#336)

feat: render the search input inside the dropdown (dowjones#309)

feat: Reduce bundle size by removing classnames (dowjones#322)

Gets rid of classnames dependency. This package was not being used for its main features anyway (just for emitting classnames conditionally).

fix: Do not hide ancestor nodes if they match 🐛 (dowjones#294)

chore: Remove unsupported peer dependency version for React

fix: Bump array.partial to support older browsers

Fixes dowjones#267

(cherry picked from commit d4466fc)

fix: Remove resetting of dropdown on init props (dowjones#265) 🐛

Keeps dropdown open if updating with new props. Only updates/sets state open if new props cause the dropdown to show (a.k.a `initial`/`always`)

dowjones#253 introduced resetting of state for shopDropdown on new props:

fix: Avoid jarring on paging (dowjones#259)

 - Avoids changing scroll if the current active descendant is the same for the tree (on prop updates on tree).
 - Also fixes jarring issue when selecting nodes on paging (index > 100/pagesize).
 - Partially fixes dowjones#257

refactor: Consolidate showDropdown props (dowjones#253) 🔨️

BREAKING CHANGE: Property changes

| Description                             | Usage before                                                | Usage after                                                   |
| --------------------------------------- | ----------------------------------------------------------- | ------------------------------------------------------------- |
| Added a new `mode` prop                 | `simpleSelect={true}` / `simpleSelect`                      | `mode='simpleSelect'`                                         |
| Bundled text props into a single object | `placeholderText='My text'`<br>`noMatchesText='No matches'` | `texts={{ placeholder: 'My text', noMatches: 'No matches' }}` |