As a PNR REST API consumer
I want to be able to easily add or update individual PNR Records within a PNR Zone
So that I don't have to provide a full PNR Record with all the PNR zones every time I make a modification

Given pnr_controller.rs provides PNR operations
When adding or updating a PNR Record
Then add a REST endpoint for PUT /anttp-0/pnr/{name}/{record} to add or update PNR Records (with key {name}) on an existing PNR Zone (with key {record})
And update utoipa annotations to the new controller endpoint
And provide a body as shown in the example below (an individual PNR Record):

```
{
  "address": "string",
  "record_type": "A",
  "ttl": 9007199254740991
}
```

Given pnr_service.rs performs changes to PNR zones and records
When adding an PNR record to an existing PNR zone
Then use append_pnr function in pnr_service.rs as an example to create update_pnr_record function, which takes a PnrRecord instead of PnrZone
And then calls update_pnr with the updated record

Implementation Notes

- Place any unit tests at the bottom of the same file as the associated production code
- Increment patch version of anttp package in Cargo.toml
- Create a copy of this issue description and save to /spec using the name of this issue as the filename (with lower underscore case, starting with the 5 char padded issue number, e.g. 00001_issue_title.txt)
- Update unit tests to validate the changes
- Update lib.rs with the new PNR endpoint and update the utoipa annotations

Amendments

- update pnr_service to trim whitespace from name and record_key variables