Close the media preview screen ASAP with sending queue enabled (#4089)

* Close the attachment preview screen ASAP when sending media with the send queue is enabled

* When the send queue FF is not enabled make sure to dismiss the screen after the media has been sent

* Make sure we get a scaled thumbnail from videos too, not only for images

* Unify several state holders into `SendActionState`.

* Fix lint issues, add `Flow.firstInstanceOf` extension fun

* Update screenshots

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Co-authored-by: ElementBot <android@element.io>

libraries/core/src/main/kotlin/io/element/android/libraries/core/coroutine/Flow.kt

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2025 New Vector Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.libraries.core.coroutine
+
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.first
+
+/*
+ * Copyright 2025 New Vector Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ * Please see LICENSE in the repository root for full details.
+ */
+
+/**
+ * Returns the first element of the flow that is an instance of [T], waiting for it if necessary.
+ */
+suspend inline fun <reified T> Flow<*>.firstInstanceOf(): T {
+    return first { it is T } as T
+}