TECH-15245: alias unpack to table.unpack

[hislopzach]

Adding an alias for unpack to table.unpack to ensure compatability for scripts written for lua 5.1 that are now being run on 5.4. Impetus for this change is test failures for Graphql Pro subscriptions in my web passion project (https://buildkite.com/invoca/web/builds/97869#0195ab45-a052-41d4-b039-d868b0815148)

From Lua 5.2 reference manual

Function unpack was moved into the table library and therefore must be called as table.unpack.