refactor(rome_formatter): Part 5: Comments formatting

[MichaReiser]

Summary

This PR is part of the comments refactoring #3227.

• It removes the old builders for formatting the leading and trailing token trivia and introduces new builders to format the leading, dangling, and trailing node comments.
• Introduces a new soft_line_indent_or_spaced builder that replaces format_delimited(..).soft_block_or_spaces()
• Deletes the no longer needed GroupsElementsBuffer (yay)
• Removes any (release) state from FormatState as it is no longer necessary to track the last token to know if spaces must be inserted between the last token and comments (is now the responsibility of the formatter that calls format_dangling_comments).

Test Plan

Added a doc test for the new soft_line_indent_or_spaced builder.