fix(AppNavBar): make navbar buttons render correctly again

We've introduced a regression in
9f633f0fcc
where model data for navbar buttons are malformed, which results in them being rendered
incorrectly (as letter identicons, instead of icon buttons)

The reason this was happening was because the model data for the
navbar buttons was not properly initialized due to a mixed usage of
positioned and named arguments of the `initItem()` APIs in `SectionItem`
models.

Fixes #5949

src/app/modules/main/module.nim

@@ -292,7 +292,7 @@ method load*[T](
   amISectionAdmin = false,
   description = "",
   image = "",
-  conf.COMMUNITIESPORTAL_SECTION_ICON,
+  icon = conf.COMMUNITIESPORTAL_SECTION_ICON,
   color = "",
   hasNotification = false,
   notificationsCount = 0,
@@ -307,7 +307,7 @@ method load*[T](
   amISectionAdmin = false,
   description = "",
   image = "",
-  conf.WALLET_SECTION_ICON,
+  icon = conf.WALLET_SECTION_ICON,
   color = "",
   hasNotification = false,
   notificationsCount = 0,
@@ -322,7 +322,7 @@ method load*[T](
   amISectionAdmin = false,
   description = "",
   image = "",
-  conf.BROWSER_SECTION_ICON,
+  icon = conf.BROWSER_SECTION_ICON,
   color = "",
   hasNotification = false,
   notificationsCount = 0,
@@ -338,7 +338,7 @@ method load*[T](
   amISectionAdmin = false,
   description = "",
   image = "",
-  conf.NODEMANAGEMENT_SECTION_ICON,
+  icon = conf.NODEMANAGEMENT_SECTION_ICON,
   color = "",
   hasNotification = false,
   notificationsCount = 0,
@@ -354,7 +354,7 @@ method load*[T](
   amISectionAdmin = false,
   description = "",
   image = "",
-  conf.SETTINGS_SECTION_ICON,
+  icon = conf.SETTINGS_SECTION_ICON,
   color = "",
   hasNotification = self.calculateProfileSectionHasNotification(),
   notificationsCount = 0,