Auto merge of #13379 - DropDemBits:ide-assists-format-args-capture, r=Veykril

internal: Migrate `ide_assists::utils` and `ide_assists::handlers` to use format arg captures (part 1)

This not only serves as making future migration to mutable syntax trees easier, it also finds out what needs to be migrated in the first place.

~~Aside from the first commit, subsequent commits are structured to only deal with one file/handler at a time.~~

This is the first of 3 PRs, migrating:

Utils:

- `gen_trait_fn_body`
- `render_snippet`
- `ReferenceConversion`
  - `convert_type`
  - `getter`

Handlers:

- `add_explicit_type`
- `add_return_type`
- `add_turbo_fish`
- `apply_demorgan`
- `auto_import`
- `convert_comment_block`
- `convert_integer_literal`
- `convert_into_to_from`
- `convert_iter_for_each_to_for`
- `convert_let_else_to_match`
- `convert_tuple_struct_to_named_struct`
- `convert_two_arm_bool_match_to_matches_macro`
- `destructure_tuple_binding`
- `extract_function`
- `extract_module`
- `extract_struct_from_enum_variant`
- `extract_type_alias`
- `extract_variable`
- `fix_visibility`

diff --cc crates/ide-assists/src/handlers/auto_import.rs
Simple merge

diff --cc crates/ide-assists/src/utils.rs
Simple merge