Revisit error status definition

[yorugac]

In PR #169, error was added to the possible statuses of the CR. Currently, this state happens only on insufficient number of VUs.
In PR #401, error upon loading output from initializer pod has also been added as error state.

Consider all the cases when the test run should enter that state and adjust the logic accordingly.

Related issue: #75
Review and close it as needs be.

Docs on k6 error codes:

• https://k6.io/docs/javascript-api/error-codes/
• https://k6.io/docs/cloud/cloud-reference/test-status-codes/

[yorugac]

In case of cloud output, failed authentication should cause error state. Right now, error is just logged by the operator while initializer pod exits successfully. K6 resource is stuck in "initialization" and is not being cleaned up.

Consider: missing token case.