[chestshop] Use Paper's native Adventure instead of bundling/relocating it

ChestShop failed to enable with NoClassDefFoundError for relocated Adventure classes (…Libs/Kyori/…/MiniMessage, then …/dialog/DialogLike): it bundled + relocated a whole Adventure stack (api, platform-bukkit, minimessage, serializers) whose versions were internally inconsistent, so the shade was missing classes.

Treasury and Business don't bundle Adventure at all — they use Paper's native copy. Aligned ChestShop with them:

• Dropped the net.kyori relocation and the bundled Adventure deps (adventure-platform-bukkit, -text-serializer-gson, -text-minimessage); excluded net.kyori from the bundled MineDown/lang libs so they resolve against Paper's Adventure.
• adventure-text-serializer-gson is now compileOnly (Paper provides it at runtime).
• Replaced BukkitAudiences.create(...) + getAudiences().sender(x)/.player(x) with native sends (CommandSender/Player are Audience on Paper); removed the unused @Deprecated getComponents() (BungeeComponentSerializer) method.

Jar shrank 7.2 MB → 6.1 MB. Verified: ChestShop enables and the market tracker starts.