feat(editor): add WTBR (Token Reward) open catalog format

Open replacement for AzerothCore's currency_token_reward SQL
table plus the per-vendor token redemption rows in npc_vendor.
Each entry says "spend N copies of token X to receive reward Y",
with reward type polymorphism: Y can be an item, a spell (taught
to the character), a title, a mount, a companion pet, a currency
conversion, an heirloom unlock, or a cosmetic (tabard / pennant /
fluff). The rewardId field's interpretation depends on the
rewardKind enum.

Distinct from WTKN (Token catalog) which defines the token
currency items themselves. WTKN says "the Champion's Seal exists
as item 44990"; WTBR says "spend 25 Champion's Seals at Argent
Tournament for the Squire's Belt (item 45517)".

Eight rewardKind values cover the full reward space (Item / Spell
/ Title / Mount / Pet / Currency / Heirloom / Cosmetic), and an
8-tier requiredFactionStanding gates by reputation
(Hated / Hostile / Unfriendly / Neutral / Friendly / Honored /
Revered / Exalted) when paired with a non-zero requiredFactionId.

Cross-references back to WTKN (spentTokenItemId), WIT (Item
rewards), WSPL (Spell rewards), WTIT (Title rewards), WMOU
(Mount rewards), WCMP (Pet rewards), WCTR (Currency conversion
rewards), and WFAC (faction-rep gating). findByToken(itemId)
is the engine helper used by vendor frames to populate the
"what can I buy with these?" list.

Three preset emitters: --gen-tbr (5 raid tier-token redemptions
consuming Trophy of the Crusade and Emblem of Frost),
--gen-tbr-pvp (5 PvP rewards spanning honor / arena / conquest
plus title and tabard kinds), --gen-tbr-faction (5 faction-
gated rewards demonstrating each standing tier from Honored
through Exalted).

Validation enforces id+name+spentTokenItemId+spentTokenCount
presence, rewardKind 0..7, requiredFactionStanding 0..7, no
duplicate ids; warns on:
  - rewardId=0 (no actual reward, vendor offers entry but
    grants nothing)
  - requiredFactionStanding > Neutral with requiredFactionId=0
    (rep gate has no faction to check)
  - Currency conversion item -> itself (typo / config bug)

Wired through the cross-format table; WTBR appears automatically
in all 18 cross-format utilities. Format count 87 -> 88; CLI
flag count 1034 -> 1039.

tools/editor/cli_arg_required.cpp

@@ -270,6 +270,8 @@ const char* const kArgRequired[] = {
     "--gen-bkd", "--gen-bkd-battle", "--gen-bkd-profession",
     "--info-wbkd", "--validate-wbkd",
     "--export-wbkd-json", "--import-wbkd-json",
+    "--gen-tbr", "--gen-tbr-pvp", "--gen-tbr-faction",
+    "--info-wtbr", "--validate-wtbr",
     "--gen-weather-temperate", "--gen-weather-arctic",
     "--gen-weather-desert", "--gen-weather-stormy",
     "--gen-zone-atmosphere",