[Bug] Ensure remote codec used for all payloads in and out

[cretz]

Describe the bug

When setting --codec-endpoint it appears to set a custom data converter globally for a few uses, but we need to make sure it's used for all input and ouput payloads (that are not search attributes)

[bergundy]

Also related: https://github.com/temporalio/cli/issues/22

[lorensr]

User reports JSON not getting decoded in:

temporal workflow show --codec-endpoint=[endpoint] --output=json

[cretz]

(will also be implicitly solved by #415 and CLI rework btw)