Sort all variables, outputs, arguments and blocks in resource block.

Adjust code file's style.
Add `numeric = false` for `random_string.name` in `201-mysql-fs-db` module as the name is used as `azurerm_mysql_flexible_server.default`'s `administrator_login` and the login name doesn't support a name start with number.
Add minimum constraints for `random_password.password` in `201-mysql-fs-db` module as the password required a minimum complexity.

quickstart/201-mysql-fs-db/variables.tf

@@ -1,9 +1,9 @@
-variable "resource_group_name_prefix" {
-  default     = "rg"
-  description = "Prefix of the resource group name that's combined with a random ID so name is unique in your Azure subscription."
-}
-
 variable "resource_group_location" {
   default     = "eastus"
   description = "Location of the resource group."
 }
+
+variable "resource_group_name_prefix" {
+  default     = "rg"
+  description = "Prefix of the resource group name that's combined with a random ID so name is unique in your Azure subscription."
+}