Add an annotation to UserSignup for captcha annotated assessment

[rajivnathan]

Description

Adds a constant for the captcha annotated assessment to be used as an annotation key in the UserSignup.

https://issues.redhat.com/browse/SANDBOX-626

eg.

apiVersion: toolchain.dev.openshift.com/v1alpha1
kind: UserSignup
metadata:
  annotations:
    toolchain.dev.openshift.com/captcha-annotated-assessment: "FRAUDULENT"
...

The other possible value is LEGITIMATE

Checks

1. Did you run make generate target? no

2. Did make generate change anything in other projects (host-operator, member-operator)? no

3. In case of new CRD, did you the following? no

   • make/generate.mk in this repository
   • resources/setup/roles/host.yaml in the sandbox-sre repository
   • PROJECT file: https://github.com/codeready-toolchain/host-operator/blob/master/PROJECT
   • CSV file: https://github.com/codeready-toolchain/host-operator/blob/master/config/manifests/bases/host-operator.clusterserviceversion.yaml

4. In case other projects are changed, please provides PR links.

   • host-operator: Annotate captcha assessments host-operator#1043