Issue 23: Added progress indicators and cancellation (#34)

- Wrapped all table operations in a new foreground job context, which mediates foreground tasks.
- Added cancellation support and partial results for table read operations.
- Added the "mark" command, which can mark, unmark & toggle marked items
- Added support for alias arguments.
- Removed the "unmark" command, and replaced it as an alias to the "marked" command
- Fixed seg faults raised when there is no table shown in the result set.

cmd/dynamo-browse/main.go

@@ -16,6 +16,7 @@ import (
 	"github.com/lmika/audax/internal/dynamo-browse/providers/settingstore"
 	"github.com/lmika/audax/internal/dynamo-browse/providers/workspacestore"
 	"github.com/lmika/audax/internal/dynamo-browse/services/itemrenderer"
+	"github.com/lmika/audax/internal/dynamo-browse/services/jobs"
 	keybindings_service "github.com/lmika/audax/internal/dynamo-browse/services/keybindings"
 	"github.com/lmika/audax/internal/dynamo-browse/services/tables"
 	workspaces_service "github.com/lmika/audax/internal/dynamo-browse/services/workspaces"
@@ -94,10 +95,12 @@ func main() {
 	tableService := tables.NewService(dynamoProvider, settingStore)
 	workspaceService := workspaces_service.NewService(resultSetSnapshotStore)
 	itemRendererService := itemrenderer.NewService(uiStyles.ItemView.FieldType, uiStyles.ItemView.MetaInfo)
+	jobsService := jobs.NewService(eventBus)
 
 	state := controllers.NewState()
-	tableReadController := controllers.NewTableReadController(state, tableService, workspaceService, itemRendererService, eventBus, *flagTable)
-	tableWriteController := controllers.NewTableWriteController(state, tableService, tableReadController, settingStore)
+	jobsController := controllers.NewJobsController(jobsService, eventBus, false)
+	tableReadController := controllers.NewTableReadController(state, tableService, workspaceService, itemRendererService, jobsController, eventBus, *flagTable)
+	tableWriteController := controllers.NewTableWriteController(state, tableService, jobsController, tableReadController, settingStore)
 	columnsController := controllers.NewColumnsController(eventBus)
 	exportController := controllers.NewExportController(state, columnsController)
 	settingsController := controllers.NewSettingsController(settingStore)
@@ -114,6 +117,7 @@ func main() {
 		columnsController,
 		exportController,
 		settingsController,
+		jobsController,
 		itemRendererService,
 		commandController,
 		keyBindingController,
@@ -122,9 +126,11 @@ func main() {
 
 	// Pre-determine if layout has dark background.  This prevents calls for creating a list to hang.
 	osstyle.DetectCurrentScheme()
-	
+
 	p := tea.NewProgram(model, tea.WithAltScreen())
 
+	jobsController.SetMessageSender(p.Send)
+
 	log.Println("launching")
 	if err := p.Start(); err != nil {
 		fmt.Printf("Alas, there's been an error: %v", err)