Remove insights (#23952)

* removed server side

* Updated store layer

* unused import

* Updated autogenerated code template

* Updated tests

* lint fix

* unused translations

* webapp side

* Updated i18n

* lint fix:

* type fix

* Updated snapshots

* Removed insights from API specs

* updated e2e

* Updated e2e tests

* Updated e2e tests

* Removed insights tests

* Removed Insights as possible channel to load in sidebar from test

* Removed more insights tests

* More e2e fixed

* More cleanup

* Lint

* More cleanup in client4 and boards api

* More cleanup

* Fixes

* lint fix

---------

Co-authored-by: maria.nunez <maria.nunez@mattermost.com>
Co-authored-by: Mattermost Build <build@mattermost.com>

server/channels/api4/handlers.go

@@ -216,11 +216,3 @@ func minimumProfessionalLicense(c *Context) *model.AppError {
 	}
 	return nil
 }
-
-func rejectGuests(c *Context) *model.AppError {
-	if c.AppContext.Session().Props[model.SessionPropIsGuest] == "true" {
-		err := model.NewAppError("", model.NoTranslation, nil, "insufficient permissions as a guest user", http.StatusNotImplemented)
-		return err
-	}
-	return nil
-}