[IndexFilters] Use context provider for IndexFilters mode state (#10490)

### WHY are these changes introduced?

Linked to Shopify/web#96682

We want to perform actions in other components whenever we enter the
non-default mode of the IndexFilters. This currently is limited to
disabling the actions in the `Page` component, but could be extended in
the future.

### WHAT is this pull request doing?

Adding a new context manager, `IndexFiltersManager`, which allows both
the IndexFilters component to use the `mode`, but also allows other
components, within Polaris and also within consumers of Polaris, to
react to the changes of the `mode`.

<!-- ℹ️ Delete the following for small / trivial changes -->

### How to 🎩

🖥 [Local development
instructions](https://github.com/Shopify/polaris/blob/main/README.md#local-development)
🗒 [General tophatting
guidelines](https://github.com/Shopify/polaris/blob/main/documentation/Tophatting.md)
📄 [Changelog
guidelines](https://github.com/Shopify/polaris/blob/main/.github/CONTRIBUTING.md#changelog)

- Spinstance:
https://admin.web.if-disable-buttons.marc-thomas.eu.spin.dev/store/shop1/orders?inContextTimeframe=none
- Storybook:
https://5d559397bae39100201eedc1-objwwxomnz.chromatic.com/?path=/story/all-components-indexfilters--wrapped-in-a-page

### 🎩 checklist

- [x] Tested on
[mobile](https://github.com/Shopify/polaris/blob/main/documentation/Tophatting.md#cross-browser-testing)
- [x] Tested on [multiple
browsers](https://help.shopify.com/en/manual/shopify-admin/supported-browsers)
- [x] Tested for
[accessibility](https://github.com/Shopify/polaris/blob/main/documentation/Accessibility%20testing.md)
- [x] Updated the component's `README.md` with documentation changes
- [x] [Tophatted
documentation](https://github.com/Shopify/polaris/blob/main/documentation/Tophatting%20documentation.md)
changes in the style guide

Author: mrcthms

.changeset/lucky-wombats-push.md

@@ -0,0 +1,5 @@
+---
+'@shopify/polaris': minor
+---
+
+Add new `IndexFiltersManager` for allowing disabling of Page Header actions when in Filtering or EditingColumns mode

polaris-react/src/components/AppProvider/AppProvider.tsx

@@ -12,6 +12,7 @@ import {
   ScrollLockManager,
   ScrollLockManagerContext,
 } from '../../utilities/scroll-lock-manager';
+import {IndexFiltersManager} from '../../utilities/index-filters';
 import {
   StickyManager,
   StickyManagerContext,
@@ -179,7 +180,7 @@ export class AppProvider extends Component<AppProviderProps, State> {
                     <PortalsManager>
                       <FocusManager>
                         <EphemeralPresenceManager>
-                          {children}
+                          <IndexFiltersManager>{children}</IndexFiltersManager>
                         </EphemeralPresenceManager>
                       </FocusManager>
                     </PortalsManager>