uses the count bus in the kopia backup package.
This currently duplicates counts that we're getting
from the kopia stats. A later pr will remove the old
stats entirely in favor of the counter.
---
#### Does this PR need a docs update or release note?
- [x] ⛔ No
#### Type of change
- [x] 🧹 Tech Debt/Cleanup
#### Test Plan
- [x] ⚡ Unit test
- [x] 💚 E2E
Adds context embedding to pkg/count, and embeds
the backup, restore, and export operation ctx with the operations count.bus. The bus is extracted from the ctx in api middleware to track throttling response counts, as well as token consumption counts. Counts are globally tracked, not on a per-time or per resource basis.
---
#### Does this PR need a docs update or release note?
- [x] ⛔ No
#### Type of change
- [x] 🌻 Feature
#### Test Plan
- [x] ⚡ Unit test
- [x] 💚 E2E
Introduces a counting bus, and threads it into restore operations so that we can count the number of
collision skips that occur.
---
#### Does this PR need a docs update or release note?
- [x] ⛔ No
#### Type of change
- [x] 🌻 Feature
#### Issue(s)
* #3562
#### Test Plan
- [x] ⚡ Unit test
- [x] 💚 E2E
