feat(pack): replace FTB Chunks with Open Parties and Claims and Xaero's maps

FTB Chunks is the only mod in the FTB suite that nothing else depends on --
FTB Quests requires FTB Library and FTB Teams only, and ships no claim-chunk
task type -- so it can leave without touching quests. Open Parties and Claims
takes over claims and force-loading, and the Xaero's suite restores the
minimap, world map and waypoints that b0542f9 removed.

The three Xaero's entries are byte-identical to the ones b0542f9 deleted, so
this reverts the map half of that commit rather than integrating anything new.
Xaero's + OPAC is also the pairing both projects document: the world map
displays OPAC claims and lets you claim and forceload from the map screen.

Drops config/ftbchunks-client.snbt and the .packwizignore negation that
shipped it, since the FTB Chunks minimap it enabled no longer exists. Also
keeps authoring/review material and migration scratch out of the pack index.

Server-side follow-up (not shippable, lives in the world save): set
maxPlayerClaimForceloads to 25, point primaryPartySystem at FTB Teams, and
decide claims.forceload.offlineForceload.

mods/open-parties-and-claims.pw.toml

@@ -0,0 +1,13 @@
+name = "Open Parties and Claims"
+filename = "open-parties-and-claims-neoforge-1.21.1-0.31.6.jar"
+side = "both"
+
+[download]
+url = "https://cdn.modrinth.com/data/gF3BGWvG/versions/3i48dTzz/open-parties-and-claims-neoforge-1.21.1-0.31.6.jar"
+hash-format = "sha512"
+hash = "6f8f2d570b6f674a9180576524b3ba507a3ad046ff319353cee50738644bf46c03ca460fb7c6880eed76f07eb2a26a983166d2510951202af86b3e120b743181"
+
+[update]
+[update.modrinth]
+mod-id = "gF3BGWvG"
+version = "3i48dTzz"