Traversal ids queries

What does this MR do?

Closes #230456 (closed)

Currently to query the namespace hierarchy we must use recursive methods through Gitlab::ObjectHierarchy. We can query the namespace hierarchy a lot faster and easier if we store the path from the root ancestor to each namespace as an attribute on the namespace. We will store this on a new traversal_id attribute on Namespaces.

Say we have this Namespace hierarchy...

graph TD;
    gitlab-->backend;
    backend-->create;
    backend-->manage;
    create-->source;
    manage-->access;
    gitlab-->frontend;

Then the path from gitlab to access is gitlab / backend / manage / access. The path from gitlab to source is gitlab / backend / create / source.

We can use this structure for fast queries. If the current namespace is backend then all our descendants match the path gitlab / backend / *, all our ancestors match the path * / backend, and everyone in the same Namespace hierarchy matches gitlab / *.

We store that path using an array of Namespace ids in a new column on Namespace called traversal_ids.

The recursive Namespace query methods have been moved to a module at app/models/concerns/namespace/recursive_traversal.rb. Feature flags have been included to toggle between using recursive and linear querying methods.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• 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

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If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
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ee/app/assets/javascripts/vue_shared/license_compliance/license_management.vue

@@ -30,10 +30,6 @@ export default {
   data() {
     return {
       formIsOpen: false,
-      tableHeaders: [
-        { className: 'section-70', label: s__('Licenses|Policy') },
-        { className: 'section-30', label: s__('Licenses|Name') },
-      ],
     };
   },
   computed: {
@@ -109,13 +105,8 @@ export default {
         </div>
 
         <template v-else>
-          <div
-            class="table-section gl-d-flex gl-pl-2"
-            :class="tableHeaders[0].className"
-            role="rowheader"
-          >
-            {{ tableHeaders[0].label }}
-
+          <div class="table-section gl-d-flex gl-pl-2 section-70" role="rowheader">
+            {{ s__('Licenses|Policy') }}
             <gl-icon
               v-if="isTooltipEnabled"
               ref="reportInfo"
@@ -146,8 +137,8 @@ export default {
             </gl-popover>
           </div>
 
-          <div class="table-section" :class="tableHeaders[1].className" role="rowheader">
-            {{ tableHeaders[1].label }}
+          <div class="table-section section-30" role="rowheader">
+            {{ s__('Licenses|Name') }}
           </div>
         </template>
       </template>