Implement push notification toggle in device detail

[germain-gg]

Implements the UI side of https://github.com/matrix-org/matrix-spec-proposals/pull/3881 Fixes https://element-io.atlassian.net/browse/PSG-708

Acceptance criterias:

• [x] Pushers are loaded with device list GET /_matrix/client/v3/pushers
• [x] For devices with a related pusher, the push notification toggle is displayed in the session overview screen
• [x] For devices without a related pusher, the push notifications section is not displayed
• [x] Toggling the toggle sets the enabled property on the Pusher using POST /_matrix/client/v3/pushers/set
• [x] any pusher without an enabled field should be treated as if enabled is false
• [x] When there is no server support for setting is_disabled (see /versions response), the toggle should be disabled

Checklist

• [ ] Tests written for new code (and old code if feasible)
• [x] Linter and other CI checks pass
• [x] Sign-off given on the changes (see CONTRIBUTING.md)

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Here's what your changelog entry will look like:

✨ Features

• Implement push notification toggle in device detail (#9308).