feat: refactor numerous areas and tokenize string literals where possible; also fixes some small bugs (#487)

Co-authored-by: Duncan Brown <duncan@bhs-consultants.com>

project.godot

@@ -294,11 +294,21 @@ _global_script_classes=[ {
 "language": "GDScript",
 "path": "res://addons/escoria-core/game/core-scripts/esc_player.gd"
 }, {
+"base": "Node",
+"class": "ESCProjectSettingsManager",
+"language": "GDScript",
+"path": "res://addons/escoria-core/game/project_settings_manager.gd"
+}, {
 "base": "Object",
 "class": "ESCResourceCache",
 "language": "GDScript",
 "path": "res://addons/escoria-core/game/core-scripts/esc_resource_cache.gd"
 }, {
+"base": "Object",
+"class": "ESCResourceDescriptor",
+"language": "GDScript",
+"path": "res://addons/escoria-core/game/core-scripts/resources/esc_resource_descriptor.gd"
+}, {
 "base": "Node2D",
 "class": "ESCRoom",
 "language": "GDScript",
@@ -379,6 +389,11 @@ _global_script_classes=[ {
 "language": "GDScript",
 "path": "res://addons/escoria-core/game/core-scripts/esc/commands/enable_terrain.gd"
 }, {
+"base": "Node",
+"class": "Escoria",
+"language": "GDScript",
+"path": "res://addons/escoria-core/game/escoria.gd"
+}, {
 "base": "ESCBaseCommand",
 "class": "HideMenuCommand",
 "language": "GDScript",
@@ -612,7 +627,9 @@ _global_script_class_icons={
 "ESCObject": "",
 "ESCObjectManager": "",
 "ESCPlayer": "res://addons/escoria-core/design/esc_player.svg",
+"ESCProjectSettingsManager": "",
 "ESCResourceCache": "",
+"ESCResourceDescriptor": "",
 "ESCRoom": "res://addons/escoria-core/design/esc_room.svg",
 "ESCRoomManager": "",
 "ESCSaveGame": "",
@@ -629,6 +646,7 @@ _global_script_class_icons={
 "ESCUtils": "",
 "ESCWalkContext": "",
 "EnableTerrainCommand": "",
+"Escoria": "",
 "HideMenuCommand": "",
 "IncGlobalCommand": "",
 "InventoryAddCommand": "",