Fixed odr violation from trying to separate constexpr functions into declaration and definition in separate files. Modified code gen to be in line with current code.

reference/esx_reader.fragment.hpp

@@ -0,0 +1,20 @@
+enum class RecordType {
+        AACT, ACHR, ACTI, ADDN, ALCH, AMMO, ANIO, APPA, ARMA, ARMO, ARTO, ASPC,
+        ASTP, AVIF, BOOK, BPTD, CAMS, CELL, CLAS, CLDC, CLFM, CLMT, COBJ, COLL,
+        CONT, CPTH, CSTY, DEBR, DIAL, DLBR, DLVW, DOBJ, DOOR, DUAL, ECZN, EFSH,
+        ENCH, EQUP, EXPL, EYES, FACT, FLOR, FLST, FSTP, FSTS, FURN, GLOB, GMST,
+        GRAS, GRUP, HAIR, HAZD, HDPT, IDLE, IDLM, IMAD, IMGS, INFO, INGR, IPCT,
+        IPDS, KEYM, KYWD, LAND, LCRT, LCTN, LENS, LGTM, LIGH, LSCR, LTEX, LVLI,
+        LVLN, LVSP, MATO, MATT, MESG, MGEF, MISC, MOVT, MSTT, MUSC, MUST, NAVI,
+        NAVM, NOTE, NPC_, OTFT, PACK, PARW, PBAR, PBEA, PCON, PERK, PFLA, PGRE,
+        PHZD, PLYR, PMIS, PROJ, PWAT, QUST, RACE, REFR, REGN, RELA, REVB, RFCT,
+        RGDL, SCEN, SCOL, SCPT, SCRL, SHOU, SLGM, SMBN, SMEN, SMQN, SNCT, SNDR,
+        SOPM, SOUN, SPEL, SPGD, STAT, TACT, TES4, TREE, TXST, VOLI, VTYP, WATR,
+        WEAP, WOOP, WRLD, WTHR, 
+};
+[[nodiscard]] std::optional<std::string_view> group_type_to_name(GroupType group_type) noexcept
+[[nodiscard]] std::optional<FourCC> record_type_to_fourcc(RecordType record_type) noexcept
+[[nodiscard]] std::optional<RecordType> fourcc_to_record_type(FourCC fourcc) noexcept
+[[nodiscard]] std::optional<std::string_view> record_type_to_name(RecordType record_type) noexcept
+[[nodiscard]] std::optional<std::string_view> flag_to_description(Flag flag) noexcept
+[[nodiscard]] std::optional<std::string_view> refr_flag_to_description(RefrFlag refr_flag) noexcept