feat: Add variableResolver to separate the namespaces.

[He-Pin]

Motivation:
Instead of adding methods to std, adding them to a separate namespace seems better and safer.

local input = {
                  "name": "Alice",
                  "welcome": "Hello Alice!"
              };

tb.objectReplaceKey(input,"name", "newName")

Here we bind the objectReplaceKey function to tb, and then get the right result.

{"newName":"Alice","welcome":"Hello Alice!"}