Rename PreviewParameterProvider subclasses to the PreviewParam suffix

The `Provider` suffix reads as a dependency provider rather than as preview
data, and it collides with the real providers in the codebase — `StringProvider`,
`PickerProvider`, the login feature's `AccountProvider` — so the name says
nothing about which of the two a class is. `PreviewParam` says it.

195 classes are renamed, along with the 185 files named after them, the konsist
rule that enforces the convention, the presentation-class file templates and the
onboarding documentation.

This cannot be split. `Konsist.scopeFromProduction()` scans the whole project, so
flipping the assertion before every class has moved leaves the rule red, and a
rule that accepted either suffix during a transition would be exactly the kind of
compatibility layer this convention change is meant to remove.

Two judgement calls in the rule itself. The `name.endsWith("PreviewProvider")`
exclusion is dropped: its only job was to reject a redundant `Preview` before
`Provider`, and the new suffix already contains it; no class currently ends with
`PreviewProvider`, so removing it changes nothing today. And
`EditableAvatarViewUriProvider` is renamed rather than deleted from the exclusion
list even though no such class exists in this repository, since it presumably
comes from the modules overlaid for the enterprise build.

Nothing keyed off the old suffix: no snapshot filename contains a provider class
name, so no Paparazzi image changes, and the Kover variants match on `*Presenter`,
`*State` and `*ViewKt`, so coverage bounds are unaffected.

features/ftue/impl/src/main/kotlin/io/element/android/features/ftue/impl/notifications/NotificationsOptInStatePreviewParam.kt

@@ -11,7 +11,7 @@ package io.element.android.features.ftue.impl.notifications
 import androidx.compose.ui.tooling.preview.PreviewParameterProvider
 import io.element.android.libraries.permissions.api.aPermissionsState
 
-open class NotificationsOptInStateProvider : PreviewParameterProvider<NotificationsOptInState> {
+open class NotificationsOptInStatePreviewParam : PreviewParameterProvider<NotificationsOptInState> {
     override val values: Sequence<NotificationsOptInState>
         get() = sequenceOf(
             aNotificationsOptInState(),

features/ftue/impl/src/main/kotlin/io/element/android/features/ftue/impl/notifications/NotificationsOptInView.kt

@@ -178,7 +178,7 @@ private fun NotificationRow(
 @PreviewsDayNight
 @Composable
 internal fun NotificationsOptInViewPreview(
-    @PreviewParameter(NotificationsOptInStateProvider::class) state: NotificationsOptInState
+    @PreviewParameter(NotificationsOptInStatePreviewParam::class) state: NotificationsOptInState
 ) {
     ElementPreview {
         NotificationsOptInView(

features/ftue/impl/src/main/kotlin/io/element/android/features/ftue/impl/sessionverification/choosemode/ChooseSelfVerificationModeStatePreviewParam.kt

@@ -12,7 +12,7 @@ import androidx.compose.ui.tooling.preview.PreviewParameterProvider
 import io.element.android.features.logout.api.direct.aDirectLogoutState
 import io.element.android.libraries.architecture.AsyncData
 
-class ChooseSelfVerificationModeStateProvider :
+class ChooseSelfVerificationModeStatePreviewParam :
     PreviewParameterProvider<ChooseSelfVerificationModeState> {
     override val values = sequenceOf(
         aChooseSelfVerificationModeState(

features/ftue/impl/src/main/kotlin/io/element/android/features/ftue/impl/sessionverification/choosemode/ChooseSelfVerificationModeView.kt

@@ -149,7 +149,7 @@ private fun ChooseSelfVerificationModeButtons(
 @PreviewsDayNight
 @Composable
 internal fun ChooseSelfVerificationModeViewPreview(
-    @PreviewParameter(ChooseSelfVerificationModeStateProvider::class) state: ChooseSelfVerificationModeState
+    @PreviewParameter(ChooseSelfVerificationModeStatePreviewParam::class) state: ChooseSelfVerificationModeState
 ) = ElementPreview {
     ChooseSelfVerificationModeView(
         state = state,