Add Slash Command Permissions support.

[TheGamerX20]

Summary

This pull request adds support for Slash Command Permissions by using:
"has_role", 'has_any_role", "is_user" and "is_owner" from discord.app.commands.
Also adds an example "slash_perms.py" in "examples/app_commands/".

Fixes Issues (#93) and (#247)

Checklist

• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes.
• 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, typehinting, ...)

[BobDotCom]

@TheGamerX20 could you take a look at these suggestions?

[TheGamerX20]

@TheGamerX20 could you take a look at these suggestions?

Hey, I am sorry for the wait, I did look at them and will commit them soon but I have been working on some changes according to feedback as outlined in Pycord's Discord server here: https://discord.com/channels/881207955029110855/881735314987708456/899998877598494850

work is done, just wanna make sure there are no bugs/issues before committing :)

[BobDotCom]

There are some merge conflicts here. They should be resolved by moving the file to discord/commands/commands.py.

[TheGamerX20]

There are some merge conflicts here. They should be resolved by moving the file to discord/commands/commands.py.

Fixed the Merge Conflicts.

The base branch was changed.

[Dorukyum]

Looks good, thanks

[Dorukyum]

Slash command groups are missing permissions which causes AttributeError: 'SlashCommandGroup' object has no attribute 'permissions' on startup.

[FrostSTeeL]

Is there any way to use it like this?

@slash.slash(name="cool_command")
async def cool_command(ctx, option):
if not ctx.author.guild_permissions.ban_members: # replace this with your desired permission
return # tell them they dont have permissions or raise an exception

instead of the role i want to check if the user has a certain guildpermission