ignore-line comments

There is currently no way to ignore spelling issues in a string

In the below snippet Harper suggests american should be American, but this is not
a valid bibliography style. There is nowhere to place an ignore comment to remove this issue

```
#set bibliography(style: /* harper:ignore */ "american-physics-society")
```

Add some form of harper: ignore-line for these use cases

**Component**
- [ x] Core engine
- [ x] Plugin/Extension
- [ ] Other: _____

Start with the Core engine and Plugin/Extension components, using the bibliography example to trace how inline comments are handled and where spelling issues are produced. Define the ignore-line behavior and its syntax, then verify that the shown bibliography style no longer reports the spelling issue while ordinary spelling checks remain active.

Written by the indexing model from the issue text.