### Description
This makes it so, if we detect the diagnostics file gets too big while
tracking an event, we just clear it and start over. Additionally, we add
an event tracking that this happened to the diagnostics file.
### Changes:
- Added `PurchasesOrchestrator` tests for paywall data sent through post
receipt
- Fixed and tested state issue with cached paywall data and failed
purchases
- Added `Integration Tests` for tracking and flushing events
- Configured `Integration Tests` with a custom documents directory to
ensure it's empty on every test invocation
- Changed deployment target on `Integration Tests` to iOS 16 to simplify
code
- Setting `Purchases.logLevel` before configuring purchases on
`Integration Tests`
- Added assertion to ensure `FileHandler` never runs on the main thread
- New `PaywallEventStore` using `FileHandler` (#2673)
- `MockFileHandler`
- `PaywallStoredEvent`: this contains the necessary information to store
an event: `PaywallEvent` + user ID
- Created `PaywallEventSerializer`
NachoSoto