Comments, revisited

[tconbeer]

This PR ended up totally rethinking and rewriting comment handling. It was spurred by #348, but ended up doing more.

For the purposes of stability, we no longer push long inline comments to be standalone comments. This also helps
preserve the meaning of the position of the inline comments (this isn't always important, but sometimes it is).

This means that sometimes lines can exceed the max desired line length (including the inline comment).

• feat: revisit comments, close Line order of comments and code is not preserved  #348
• chore: improve unit testing and docs
• fix: allow merging if lines end in trailing inline comment
• fix: allow merging ahead of inline comments'
• fix: allow merging of blank lines after inline comments
• fix: keep inline comments inline
• fix: strip whitespace when splitting comments onto multiple lines
• fix: merge through comments if directly after standalone operator
• chore: bump primer refs

[tconbeer]

Improve it