Implement error checks in grant/revoke.

src/box/alter.cc

src/box/lua/schema.lua

src/errcode.h

test/box/access.result

test/box/access_misc.result

test/box/box.net.box.result

test/box/box.net.box.test.lua

test/box/misc.result

test/box/protocol.result

test/box/protocol.test.lua

test/box/role.result

test/box/role.test.lua

test/box/session.result

test/box/session.test.lua

test/replication/cluster.result

test/replication/cluster.test.py