## Summary
Ensures that any lint rules that include line locations render them as
relative to the cell (and include the cell number) when inside a Jupyter
notebook.
Closes https://github.com/astral-sh/ruff/issues/6672.
## Test Plan
`cargo test`
## Summary
This PR adds a new `cell` field to the JSON output format which
indicates the Notebook cell this diagnostic (and fix) belongs to. It
also updates the location for the diagnostic and fixes as per the
`NotebookIndex`. It will be used in the VSCode extension to display the
diagnostic in the correct cell.
The diagnostic and edit start and end source locations are translated
for the notebook as per the `NotebookIndex`. The end source location for
an edit needs some special handling.
### Edit end location
To understand this, the following context is required:
1. Visible lines in Jupyter Notebook vs JSON array strings: The newline
is part of the string in the JSON format. This means that if there are 3
visible lines in a cell where the last line is empty then the JSON would
contain 2 strings in the source array, both ending with a newline:
**JSON format:**
```json
[
"# first line\n",
"# second line\n",
]
```
**Notebook view:**
```python
1 # first line
2 # second line
3
```
2. If an edit needs to remove an entire line including the newline, then
the end location would be the start of the next row.
To remove a statement in the following code:
```python
import os
```
The edit would be:
```
start: row 1, col 1
end: row 2, col 1
```
Now, here's where the problem lies. The notebook index doesn't have any
information for row 2 because it doesn't exists in the actual notebook.
The newline was added by Ruff to concatenate the source code and it's
removed before writing back. But, the edit is computed looking at that
newline.
This means that while translating the end location for an edit belong to
a Notebook, we need to check if both the start and end location belongs
to the same cell. If not, then the end location should be the first
character of the next row and if so, translate that back to the last
character of the previous row. Taking the above example, the translated
location for Notebook would be:
```
start: row 1, col 1
end: row 1, col 10
```
## Test Plan
Add test cases for notebook output in the JSON format and update
existing snapshots.
## Summary
As a small quality-of-life improvement, the locator can now slice like
`locator.slice(stmt)` instead of requiring
`locator.slice(stmt.range())`.
## Test Plan
`cargo test`
