Feat (RAG): tying tui calls to rag funcs [WIP; skip-ci]

RAG itself is annoying to properly implement, plucking sentences with no
context is useless. Also it should not be a part of main package, same
for goes for tui. The number of global vars is absurd.

main.go

@@ -10,7 +10,7 @@ var (
 	botRespMode   = false
 	editMode      = false
 	selectedIndex = int(-1)
-	indexLine     = "F12 to show keys help; bot resp mode: %v; char: %s; chat: %s"
+	indexLine     = "F12 to show keys help; bot resp mode: %v; char: %s; chat: %s; RAGEnabled: %v"
 	focusSwitcher = map[tview.Primitive]tview.Primitive{}
 )