feat(commands): support Annotated[tp, converter] in prefix commands

[shiftinv]

Summary

Fixes #1422.
See https://disnake--1431.org.readthedocs.build/en/1431/ext/commands/commands.html#typing-annotated for a proper explanation :>

Checklist

• If code changes were made, then they have been tested
  • I have updated the documentation to reflect the changes
  • I have formatted the code properly by running uv run nox -s lint
  • I have type-checked the code by running uv run nox -s pyright
• This PR fixes an issue
• This PR adds something new (e.g. new method or parameters)
• This PR is a breaking change (e.g. methods or parameters removed/renamed)
• This PR is not a code change (e.g. documentation, README, ...)

[read-the-docs-community]

Documentation build overview

📚 disnake | 🛠️ Build #29912016 | 📁 Comparing fd4b448 against latest (c56069b)

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Show files changed (50 files in total): 📝 50 modified | ➕ 0 added | ➖ 0 deleted

File	Status
index.html	📝 modified
whats_new.html	📝 modified
api/abc.html	📝 modified
api/activities.html	📝 modified
api/app_commands.html	📝 modified
api/app_info.html	📝 modified
api/audit_logs.html	📝 modified
api/automod.html	📝 modified
api/channels.html	📝 modified
api/clients.html	📝 modified
api/components.html	📝 modified
api/emoji.html	📝 modified
api/entitlements.html	📝 modified
api/events.html	📝 modified
api/exceptions.html	📝 modified
api/guild_scheduled_events.html	📝 modified
api/guilds.html	📝 modified
api/integrations.html	📝 modified
api/interactions.html	📝 modified
api/invites.html	📝 modified
api/localization.html	📝 modified
api/members.html	📝 modified
api/messages.html	📝 modified
api/misc.html	📝 modified
api/permissions.html	📝 modified
api/roles.html	📝 modified
api/skus.html	📝 modified
api/soundboard.html	📝 modified
api/stage_instances.html	📝 modified
api/stickers.html	📝 modified
api/subscriptions.html	📝 modified
api/ui.html	📝 modified
api/users.html	📝 modified
api/utilities.html	📝 modified
api/voice.html	📝 modified
api/webhooks.html	📝 modified
api/widgets.html	📝 modified
ext/commands/commands.html	📝 modified
ext/commands/slash_commands.html	📝 modified
ext/tasks/index.html	📝 modified
ext/commands/api/app_commands.html	📝 modified
ext/commands/api/bots.html	📝 modified
ext/commands/api/checks.html	📝 modified
ext/commands/api/cogs.html	📝 modified
ext/commands/api/context.html	📝 modified
ext/commands/api/converters.html	📝 modified
ext/commands/api/exceptions.html	📝 modified
ext/commands/api/help_commands.html	📝 modified
ext/commands/api/misc.html	📝 modified
ext/commands/api/prefix_commands.html	📝 modified