Clarify docs on Role based access control

[antejavor]

It looks like you need these permissions to create some node or relationship:

CREATE DATABASE db;
GRANT ALL PRIVILEGES TO user;
GRANT DATABASE * TO user;
GRANT CREATE_DELETE ON LABELS * TO user;
GRANT CREATE_DELETE ON EDGE_TYPES * TO user;
SHOW USERS;

It is not sufficient to do GRANT ALL PRIVILEGES TO user; GRANT DATABASE * TO user;

We should revisit: https://memgraph.com/docs/database-management/authentication-and-authorization/role-based-access-control

Context: https://discord.com/channels/842007348272169002/1278498722270937158/1283321686376190054

[hal-eisen-MG]

Some new documentation was added in https://memgraph.com/docs/database-management/multi-tenancy