* Simplify how event content with captions are displayed
The caption component will now be added in `TimelineItemEventContentView` instead of separately in each `TimelineItem__View` component
* Make sure `CoilMediaFetcher` methods to fetch media throw errors
We need to catch them later to check if the content scanner marked some thumbnails or medias as invalid/unsafe in `AsyncImage` instances
* Add a `ContentScannerService` that allows us to manually scan a list of medias in an event and then update and store the results
The results take the form of `ContentValidationValue`, stored in a `ContentValidationState` instance tied to the event
* Create `EventContentValidationCache` to keep the `ContentValidationStates` for events in a room
* Expose `EventContentValidationCache` to Compose using `LocalEventContentValidationState`
Also add a couple of helper functions to avoid having to manually remember the states
* Use the new components to display invalid content in the timeline items
* Add `blurhash` to most media items so we can use it while validating the thumbnails/medias
* Fix custom layout issues with screenshot and UI tests
* Also check the validation state for replied-to events in the composer
* Fix and add tests
* Handle unrecoverable content validation errors too: display a 'not found' UI
* Improve the performance of `EqualWidthColumn` for the single item case
* Update screenshots
---------
Co-authored-by: ElementBot <android@element.io>
* Create a `ContentScanner` component:
- Add `:features:contentscanner:api` module with the interface.
- Implement the concrete component using the Rust SDK in `:libraries:matrix:impl`.
This can be used to both set up the content scanner media fetching in the SDK Client and manually scanning media sources from the Android side
* Create `ContentScannerUrlProvider` in a new `:features:contentscaner:api` module as a noop implementation
Use it as a placeholder for the code to instantiate a `RustContentScanner` with the fetched URL and set it as part of the SDK client.
* Expose the optional `ContentScanner` in the `@SessionScope`
* Split the storage part of the Element well-known retriever so it can be reused for the non-session bound retriever.
Also add the new `content_scanner_url` field to it.
This will be used by the enterprise code to fetch the actual content scanner url.
* Bump enterprise commit to have access to the actual content scanner url provider implementation
* Fix tests and lint issues
* Use the right namespace for `:features:contentscanner:api`, also use the right namespace for `impl`
---------
Co-authored-by: Benoit Marty <benoitm@element.io>
Jorge Martin Espinosa