Tint the framed-header icons and go-to arrows on SIMPLEX

On the SIMPLEX theme the raw secondary colour is a cool blue
(#8B99D6) and the framed-header icons drew in the grey FileDark /
FileLight — both read cold over the warm sunrise gradient, while the
text around them already uses the warm tint. Route the framed-header
icon (forward / flag / moderation / deleted markers) and the resting
go-to arrow (jump-to-source on forwarded items, jump-to search hit)
through simplexSecondaryTint() on SIMPLEX. Every other theme keeps
its exact colours.

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/ChatItemView.kt

@@ -262,6 +262,8 @@ fun ChatItemView(
       }
       val iconTint = if (fullyVisible) {
         Color.White
+      } else if (CurrentColors.value.base == DefaultTheme.SIMPLEX) {
+        simplexSecondaryTint()
       } else {
         if (MaterialTheme.colors.isLight) {
           MaterialTheme.colors.secondary.mixWith(Color.White, mixAlpha)

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/chat/item/FramedItemView.kt

@@ -116,7 +116,7 @@ fun FramedItemView(
           icon,
           caption,
           Modifier.size(18.dp),
-          tint = iconColor ?: if (isInDarkTheme()) FileDark else FileLight
+          tint = iconColor ?: if (CurrentColors.value.base == DefaultTheme.SIMPLEX) simplexSecondaryTint() else if (isInDarkTheme()) FileDark else FileLight
         )
       }
       val captionColor = simplexSecondaryTint()