IDs: Introduce ID handling functions and data

IDs will be needed by multiple subsystems, so introduce the needed
variables and handling functions.

src/IDs.cpp

@@ -0,0 +1,45 @@
+//
+// Created by Teo-CD on 19/10/23.
+//
+
+#include "IDs.h"
+
+/* IDs are greater than one, offset the array to make it easier to use. */
+constexpr char promoDirs[][dirStrSize] = {
+		"INVALIDE",
+		"RANDONNEE",
+		"RESTO",
+		"AUTOBUS",
+		"MAYO",
+		"MADO",
+		"COOP",
+		"OURS",
+		"BAGAR",
+		"INCAPABLE",
+		"MYSTERE"
+};
+constexpr char charDirs[][dirStrSize] = {
+		"INVALIDE",
+		"GUILLAUME",
+		"MICHEL"
+};
+
+bool isIdGone(int8_t ID) {
+	return ID & idMaskGone;
+}
+
+bool isIdCharacter(int8_t ID) {
+	return ID & idMaskChar;
+}
+
+uint8_t getRawId(int8_t ID) {
+	return ID & ~(idMaskGone | idMaskChar);
+}
+
+bool isValidId(int8_t ID) {
+	uint8_t rawId = getRawId(ID);
+	if (isIdCharacter(ID))
+		return rawId < sizeof(charDirs) / dirStrSize;
+	else
+		return rawId < sizeof(promoDirs) / dirStrSize;
+}