lua: make most all tarantool code strict safe

extra/dist/tarantoolctl

src/box/lua/schema.lua

src/box/lua/tuple.lua

test/big/lua/utils.lua

test/big/tree_pk.result

test/big/tree_pk.test.lua

test/big/tree_variants.result

test/big/tree_variants.test.lua

test/box/alter.result

test/box/alter.test.lua

test/box/bad_trigger.result

test/box/bad_trigger.test.py

test/box/bsdsocket.result

test/box/bsdsocket.test.lua

test/box/crossjoin.result

test/box/crossjoin.test.lua

test/box/fiber.result

test/box/fiber.test.lua

test/box/lua/fiber.lua

test/box/lua/fifo.lua