With new ACL conception, access control lists in NeoFS
defined as a required basic ACL and optional extended ACL.
Basic ACL must be set up in container structure. It is a bit
mask stored in 32-bit unsigned integer.
Seven nibbles represent seven object operations: get, put,
head, search, delete, range, range-hash.
Every nibble defines access rules for three targets: user,
owner, others and has permission bit for bearer token.
There is a permission bit for extended ACL and three unused
bits.
