DAST scans site profile: Fix inprogress transition

What does this MR do?

It fixes an issue that can occur in two different scenarios:

1. Editing a DAST on-demand scans site profile, which is currently being validated
2. Creating a new profile, which shares the URL of a profile that is currently being validated

Both cases will end up in an error state (without a token) if the validation fails:

How to test this?

1. Enable the feature flag.

echo "Feature.enable(:security_on_demand_scans_site_validation)" | rails c

2. Install and setup graphql-vue-apollo-playground locally. Checkout the mock-dast-site-profiles branch and run the mock server.

3. Use the local mock server in the Apollo provider.

diff --git a/ee/app/assets/javascripts/dast_site_profiles_form/graphql/provider.js b/ee/app/assets/javascripts/dast_site_profiles_form/graphql/provider.js
index ef96b443da8..993a7cefb5c 100644
--- a/ee/app/assets/javascripts/dast_site_profiles_form/graphql/provider.js
+++ b/ee/app/assets/javascripts/dast_site_profiles_form/graphql/provider.js
@@ -5,5 +5,10 @@ import createDefaultClient from '~/lib/graphql';
 Vue.use(VueApollo);
 
 export default new VueApollo({
-  defaultClient: createDefaultClient(),
+  defaultClient: createDefaultClient(
+    {},
+    {
+      baseUrl: 'http://localhost:4000',
+    },
+  ),
 });

4. Set the status to states.INPROGRESS_VALIDATION within dast_site_validation.js (mock apollo server)

5. Navigate to the DAST Site profile form in your GDK: /:namespace/:project/-/on_demand_scans/profiles/dast_site_profiles/new

6. Fill out the form and enable validation

7. Set the status to states.FAILED_VALIDATION within dast_site_validation.js (mock apollo server) note: if the change happens at the same time as the request hits the mock server there might be an error. Please try again. Increasing DAST_SITE_VALIDATION_POLL_INTERVAL within ee/app/assets/javascripts/security_configuration/dast_site_profiles_form/constants.js can help to reduce the chance of this.

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry (behind feature flag)
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done