[SOMA-3827][SOMA-4162] Colocar warning quando tiver herdando sga_name default

- Simplicado o  uso de meta-tabelas
- Uso de raw_get para verificar se o valor estava na tabela de
configuração ou for herdado

sga/configuration.lua

@@ -6,8 +6,8 @@ local schema = require("schema")
 
 local function get(config_data, filename, config_default)
    local config = {}
-   config_default.sgas = nil -- avoid multiple inside multiple
-   config_default.__index = function (t,k) return config_default[k] end
+   config_default.sgas = nil -- avoids multiple inside multiple
+   config_default.__index = config_default -- sets default values for the configuration
    setmetatable(config, config_default)
    local chunk, err = load(config_data, filename, "t", config)
    if not chunk then
@@ -22,7 +22,13 @@ local function get(config_data, filename, config_default)
    if not ok then
       return nil, "Failed processing config file "..filename..": "..err
    end
-   return config
+
+   local warning = nil
+   -- Warns if the sga_name is being inherited from the default configuration and not explicitly declared
+   if config_default["sga_name"] and not rawget(config, "sga_name") then
+      warning = string.format("[WARNING] Config file %s contains configuration using default sga_name %s", filename, config_default["sga_name"])
+   end
+   return config, warning
 end
 
 local function get_from_multiple(filename, sga_name, config)
@@ -41,6 +47,9 @@ local function get_from_multiple(filename, sga_name, config)
    for key, data in ipairs(sgas_data) do
       local sga_config, err_msg = {}
       sga_config, err_msg = get(data, filename, config)
+      if err_msg then
+         table.insert(warning, err_msg)
+      end
       if sga_config then
          configuration.check(sga_config, true)
          if sga_config.sga_name then