Make verification screens scrollable and emoji labels multiline (#4449)

* Make self verification screens scrollable

* Remove unused fields from `VerificationEmoji`

* Make only the header and content scroll in `HeaderFooterPage`.

* Use the right 'emoji' icon in both flows (`ReactionSolid`)

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

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/verification/SessionVerificationData.kt

@@ -25,6 +25,4 @@ sealed interface SessionVerificationData {
 // https://spec.matrix.org/unstable/client-server-api/#sas-method-emoji
 data class VerificationEmoji(
     val number: Int,
-    val emoji: String,
-    val description: String,
 )