MM-26750: Remove instances of InitBasic when it's not required (#14984)

th.InitBasic initializes users, channels, and teams. But a lot of
tests don't use it at all, causing unncessary delays. A single InitBasic
call takes around 400ms. This PR removes 71 of them, approximately shaving
off 28 seconds. Arguably, this would be more because some tests run in loops.

app/command_autocomplete_test.go

@@ -198,7 +198,7 @@ func TestParseNamedArguments(t *testing.T) {
 }
 
 func TestSuggestions(t *testing.T) {
-	th := Setup(t).InitBasic()
+	th := Setup(t)
 	defer th.TearDown()
 
 	jira := createJiraAutocompleteData()
@@ -324,7 +324,7 @@ func TestSuggestions(t *testing.T) {
 }
 
 func TestCommandWithOptionalArgs(t *testing.T) {
-	th := Setup(t).InitBasic()
+	th := Setup(t)
 	defer th.TearDown()
 
 	command := createCommandWithOptionalArgs()