Draft: Refactor apollo loadingKey to computed property

What does this MR do and why?

This MR replaces occurrences of apollo's loadingKey in vulnerability/security components by adding a computed property which returns the apollo query's loading property. The discussion behind refactoring this can be found in the issue #385842 (closed), but boils down to the use of loadingKey being confusing and $apollo.queries.queryName.loading being used everywhere.

Screenshots or screen recordings

location	screenshot
vulnerability_finding_modal.vue1
tool_filter.vue2
cluster_filter.vue, cluster_filter_deprecated.vue3, image_filter.vue, image_filter_deprecated.vue3

¹to view vulnerability_finding_modal.vue, pipelineSecurityDashboardGraphql feature flag must be true.

²to view tool_filter.vue, refactorVulnerabilityFilters feature flag must be false and you must view the vulnerability report on a group level.

³to view image_filter_deprecated.vue and cluster_filter_deprecated.vue, refactorVulnerabilityFilters feature flag must be false.

How to set up and validate locally

1. You need an EE license
2. You need runners enabled
3. import security reports

vulnerability_finding_modal.vue

1. enable pipeline_security_dashboard_graphql feature flag echo "Feature.enable(:pipeline_security_dashboard_graphql)" | rails c
2. create an MR making a small change in security-reports
3. check the pipeline and go to security tab
4. set network throttling to fast 3G
5. click on a vulnerability
6. verify that loading state can be seen

cluster_filter.vue 7 image_filter.vue

1. go to the vulnerability report page of security-reports
2. set network throttling to fast 3G
3. click operational vulnerabilities tab
4. verify that both cluster and image filter show loading state for a while

cluster_filter_deprecated.vue & image_filter_deprecated.vue

1. disable refactor_vulnerability_filters feature flag echo "Feature.disable(:refactor_vulnerability_filters)" | rails c
2. go to the vulnerability report page of security-reports
3. set network throttling to fast 3G
4. click operational vulnerabilities tab
5. verify that both cluster and image filter show loading state for a while

tool_filter.vue

1. enable refactor_vulnerability_tool_filter feature flag echo "Feature.enable(:refactor_vulnerability_tool_filter)" | rails c
2. set network throttling to fast 3G
3. go to vulnerability report page of flightjs group /groups/flightjs/-/security/vulnerabilities (or other group with vulnerability report)
4. verify that tool filter shows loading state for a while

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.