fix: Use correct line num with trimmed suggestions

[Muscraft]

I came across rust-lang/rust-clippy#15883, which reported incorrect line numbers for a multi-line suggestion. I realized the incorrect line numbers were coming from rustc, which made me realize that annotate-snippets also had this problem.

The root cause of the problems comes from the process of trimming Patch's replacement to be a substring of the original. During this process, the span also gets adjusted to match the trimmed replacement. We later use this span to get the line_start when rendering the suggestion. This is where the bug happens: if the adjusted span's line_start does not match the original span's line_start, we would show incorrect line numbers.

To fix this, I made it so we track both the original span and trimmed span for Patchs, and use the original span for line_start.