core: add options to delegate BPFFS token creation

Add four new options BPFDelegate{Commands,Maps,Programs,Attachments}=
in order to delegate to a BPFFS instance the permission to create tokens.

The value is a list of options taken from:
https://github.com/torvalds/linux/blob/v6.14/include/uapi/linux/bpf.h#L922-L1121
The special value "any" means to allow every possible values.

More informations about BPF tokens here:
https://lwn.net/Articles/947173/

tools/xml_helper.py

@@ -10,6 +10,8 @@ class CustomResolver(tree.Resolver):
             return self.resolve_filename('man/custom-entities.ent', context)
         if 'ethtool-link-mode' in url:
             return self.resolve_filename('src/shared/ethtool-link-mode.xml', context)
+        if 'bpf-delegate' in url:
+            return self.resolve_filename('man/bpf-delegate.xml', context)
 
         return None