Vault creation grows heap

[turadg]

What is the Problem Being Solved?

With #7218 we learned that creating more vaults grows the heap. I.e. some objects are being retained through the vault creation that shouldn't be.

Description of the Design

Find all the retaining paths and fix them. So far,

Retention fixes

Preview Give feedback

1. fix(vaults): durable invitationMakers #7296
   automerge:rebase +1
2. fix Zoe offerResult durability handling #7294
   automerge:rebase +1
3. Durable publish kits should not hold values in RAM #7298
   enhancement notifier performance vaults_triage +4
   
4. replace pipeTopicToStorage with new utilities #7300
   enhancement vaults_triage +2
   
5. Alternative to pipeTopicToStorage #7303
   enhancement notifier vaults_triage +3
   

Then add regression tests (see Test Plan).

Security Considerations

Scaling Considerations

Test Plan

We need a test that checks memory usage growth. This may be achievable by process.memoryUsage() comparison after vault runs. See #7296 (comment)