impl: poll workspaces when Toolbox screen becomes visible

Some users complained that Coder Toolbox has a noticeable delay in rendering the workspaces
status compared with the web Dashboard, even though they have the same polling frequency,
which is every 5 seconds.
However, the web Dashboard also reacts and when the tab receives focus from the user which
improves the experience. This PR tries to implement the same behavior, when Coder Toolbox
screen becomes visible the polling is triggered immediately which should result in a status update.

Author: fioan89

src/main/kotlin/com/coder/toolbox/CoderRemoteProvider.kt

@@ -54,8 +54,8 @@ class CoderRemoteProvider(
 
     private val settings = context.settingsStore.readOnly()
 
-    // Create our services from the Toolbox ones.
     private val triggerSshConfig = Channel<Boolean>(Channel.CONFLATED)
+    private val triggerProviderVisible = Channel<Boolean>(Channel.CONFLATED)
     private val settingsPage: CoderSettingsPage = CoderSettingsPage(context, triggerSshConfig)
     private val dialogUi = DialogUi(context)
 
@@ -185,6 +185,11 @@ class CoderRemoteProvider(
                         cli.configSsh(lastEnvironments.map { it.asPairOfWorkspaceAndAgent() }.toSet())
                     }
                 }
+                triggerProviderVisible.onReceive { isCoderProviderVisible ->
+                    if (isCoderProviderVisible) {
+                        context.logger.info("workspace poller waked up, Coder Toolbox is currently visible, fetching latest workspace statuses")
+                    }
+                }
             }
             lastPollTime = TimeSource.Monotonic.markNow()
         }
@@ -293,6 +298,11 @@ class CoderRemoteProvider(
         visibilityState.update {
             visibility
         }
+        if (visibility.providerVisible) {
+            context.cs.launch {
+                triggerProviderVisible.send(true)
+            }
+        }
     }
 
     /**