cleanup: run XCode code analysis

enable ARC in CMakelist.txt
fix small potentials leaks across the client

Refs #75600

Change-Id: I72ba17e6daed393abdf38653f45c040bd3427ead
diff --git a/src/AccVideoVC.mm b/src/AccVideoVC.mm
index 862e02d..7e5ed1e 100644
--- a/src/AccVideoVC.mm
+++ b/src/AccVideoVC.mm
@@ -78,15 +78,15 @@
 {
     auto account = [self currentAccount];
 
-    treeController = [[QNSTreeController alloc] initWithQModel:[self currentAccount]->codecModel()->videoCodecs()];
+    treeController = [[QNSTreeController alloc] initWithQModel:account->codecModel()->videoCodecs()];
     [treeController setAvoidsEmptySelection:NO];
     [treeController setChildrenKeyPath:@"children"];
 
     [codecsView bind:@"content" toObject:treeController withKeyPath:@"arrangedObjects" options:nil];
     [codecsView bind:@"sortDescriptors" toObject:treeController withKeyPath:@"sortDescriptors" options:nil];
     [codecsView bind:@"selectionIndexPaths" toObject:treeController withKeyPath:@"selectionIndexPaths" options:nil];
-    [videoPanelContainer setHidden:![self currentAccount]->isVideoEnabled()];
-    [toggleVideoButton setState:[self currentAccount]->isVideoEnabled()?NSOnState:NSOffState];
+    [videoPanelContainer setHidden:!account->isVideoEnabled()];
+    [toggleVideoButton setState:account->isVideoEnabled()?NSOnState:NSOffState];
 }
 
 - (IBAction)toggleVideoEnabled:(id)sender {