Add default requires and permission methods to BasicCommand

[kennytv]

Alternative to #11046; does not deprecate the existing methods and instead opts for a simpler solution

[MiniDigger]

I still think attaching a perm node should be mandatory. We need to actively discourage using manual perm checks for root commands, since doing that over using this new method will still send the command, so players can tab complete it.
A part of me always dies whenever I see people installing tab block plugins or straight up disable tab complete in order to hide commands players don't have permission to run but still see in tab completion.
In my ideal world every root command has a perm node attached to it and it a command should be used by e everyone by default the permission to that command should just be granted by default, either by registering it in the plugin.yml or by registering it in code.