Add headers option for cli request

[nickwestmo]

Is your feature request related to a problem? Please describe.
While using the cli to a request it does not account for a header or other addition query strings at the end of the --api-uri

Describe the solution you'd like
I would like testkube to add a --Header or something of the sort so It is possible to set request headers when using the testkube cli

An example would be like
testkube get executors --client direct --api-uri https://testkube-sandbox.domain.com --headers headerinputhere

Additional context
At the moment if I add a header to the end. In this case a jwt token it will append some extra text at the end of the request. This will break the jwt token and fail the request.