Update start trial CTA in top right banner to only appear if all namespaces are free

What does this MR do?

Issue #36402 (closed)

We want to exclude any user from seeing this CTA

• if either their personal namespace
• or any group they are associated with at least reporter access is on a paid tier (Bronze, Silver or Gold).

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

Database

explain SELECT 1 AS one
FROM (
        (SELECT "namespaces"."plan_id"
         FROM "namespaces"
         WHERE "namespaces"."type" IS NULL
           AND "namespaces"."owner_id" = 4409816)
      UNION
        (SELECT "namespaces"."plan_id"
         FROM "namespaces"
         INNER JOIN "members" ON "namespaces"."id" = "members"."source_id"
         WHERE "members"."type" IN ('GroupMember')
           AND "members"."source_type" = 'Namespace'
           AND "namespaces"."type" IN ('Group')
           AND "members"."user_id" = 4409816
           AND "members"."requested_at" IS NULL
           AND "members"."access_level" IN (20,
                                            30,
                                            40,
                                            50)
           AND "namespaces"."parent_id" IS NULL)) namespaces
WHERE "namespaces"."plan_id" IN
    (SELECT "plans"."id"
     FROM "plans"
     WHERE "plans"."name" IN ('bronze',
                              'silver',
                              'gold'))
LIMIT 1;

https://explain.depesz.com/s/pVJr

Limit  (cost=31.11..33.21 rows=1 width=4) (actual time=0.266..0.268 rows=1 loops=1)
   Buffers: shared hit=48
   ->  Nested Loop  (cost=31.11..35.32 rows=2 width=4) (actual time=0.265..0.265 rows=1 loops=1)
         Buffers: shared hit=48
         ->  Seq Scan on public.plans  (cost=0.00..4.08 rows=3 width=4) (actual time=0.028..0.030 rows=3 loops=1)
               Filter: ((plans.name)::text = ANY ('{bronze,silver,gold}'::text[]))
               Rows Removed by Filter: 2
               Buffers: shared hit=1
         ->  Materialize  (cost=31.11..31.15 rows=2 width=4) (actual time=0.074..0.076 rows=2 loops=3)
               Buffers: shared hit=47
               ->  Unique  (cost=31.11..31.12 rows=2 width=4) (actual time=0.216..0.221 rows=3 loops=1)
                     Buffers: shared hit=47
                     ->  Sort  (cost=31.11..31.12 rows=2 width=4) (actual time=0.215..0.216 rows=7 loops=1)
                           Sort Key: namespaces.plan_id
                           Sort Method: quicksort  Memory: 25kB
                           Buffers: shared hit=47
                           ->  Append  (cost=0.43..31.10 rows=2 width=4) (actual time=0.013..0.161 rows=7 loops=1)
                                 Buffers: shared hit=44
                                 ->  Index Scan using index_namespaces_on_owner_id on public.namespaces  (cost=0.43..4.45 rows=1 width=4) (actual time=0.013..0.014 rows=1 loops=1)
                                       Index Cond: (namespaces.owner_id = 4409816)
                                       Filter: (namespaces.type IS NULL)
                                       Rows Removed by Filter: 0
                                       Buffers: shared hit=4
                                 ->  Nested Loop  (cost=0.87..26.63 rows=1 width=4) (actual time=0.047..0.146 rows=6 loops=1)
                                       Buffers: shared hit=40
                                       ->  Index Scan using index_members_on_user_id on public.members  (cost=0.43..22.17 rows=1 width=4) (actual time=0.028..0.064 rows=6 loops=1)
                                             Index Cond: (members.user_id = 4409816)
                                             Filter: ((members.requested_at IS NULL) AND ((members.type)::text = 'GroupMember'::text) AND ((members.source_type)::text = 'Namespace'::text) AND (members.access_level = ANY ('{20,30,40,50}'::integer[])))
                                             Rows Removed by Filter: 7
                                             Buffers: shared hit=16
                                       ->  Index Scan using namespaces_pkey on public.namespaces namespaces_1  (cost=0.43..4.45 rows=1 width=8) (actual time=0.012..0.012 rows=1 loops=6)
                                             Index Cond: (namespaces_1.id = members.source_id)
                                             Filter: ((namespaces_1.parent_id IS NULL) AND ((namespaces_1.type)::text = 'Group'::text))
                                             Rows Removed by Filter: 0
                                             Buffers: shared hit=24

Summary:

Time: 5.465 ms
  - planning: 5.069 ms
  - execution: 0.396 ms
    - I/O read: 0.000 ms
    - I/O write: 0.000 ms

Shared buffers:
  - hits: 48 (~384.00 KiB) from the buffer pool
  - reads: 0 from the OS file cache, including disk I/O
  - dirtied: 0
  - writes: 0

Security

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
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team