Localization (#15)

## Changes (escoria-core)
> Pending to do a PR to the core.
- Added `es` langcode with the corresponding flag image.
- Translated literals for `es`

## Changes (gymkhana)
-  Added `turno_cocina` localization csv.
- Proof of concept for tooltips & dialogs.

## Notes
- For tooltips just use the literals. Godot will automatically search for a translation key first.
- For ESC just use `translation_key:"Default text"`

## How to test
- In the option menu ES should be selectable.
- The `frontal` item in the inventory should have the tooltips and the `say` command translated in `en`,`fr` and `es`.

Reviewed-on: gymkhana/gymkhana#15
Co-authored-by: oier <oierbravo@gmail.com>
Co-committed-by: oier <oierbravo@gmail.com>

gymkhana/items/inventory/turno_cocina_frontal.tscn

@@ -15,7 +15,7 @@ esc_script = "res://gymkhana/items/inventory/turno_cocina_frontal.esc"
 inventory_texture = ExtResource( 2 )
 dialog_color = Color( 1, 1, 1, 1 )
 tooltips = {
-    "action3": "Admirar",
+    "action3": "frontal_action3",
     "action4": "Usar"
 }
 combine_when_selected_action_is_in = [ "action4" ]