Override permissions for subcommands, only possible on parent command

[mccormickk]

Currently, the Discord API only allows permissions to be redefined at the parent command level.
Subcommands automatically inherit the permission set of their parent command, and there is currently no mechanism to define individual permissions for each subcommand separately.

This limitation makes it difficult to implement fine-grained access control in applications where different subcommands of the same parent command require different levels of permissions.
Similar issues have been raised in the past, but several years have passed and the update has still not been released.

For example:

• /family manage edit may need to be restricted to users with the “Moderator” role.
• /family info may be intended for all server members.

Currently, both subcommands inherit the same set of permissions from /family, which does not allow for detailed control.

[Soheab]

Dup of #7813 & #4719