fix: Suppress extra indent after the end of field and function chains

[DropDemBits]

(spurred on by #4182 (comment))

Caveat that this doesn't work for after tail expressions, although there shouldn't be anything after those anyways.

This also complicates when to reload the language configuration by nature of now always having a language configuration applicable.

Examples of indentation fixes:

fn main() {
    println!("Hello!"); // < enter here!
    // ... indents down here

    fs::read_to_string("soup") // < enter here!
    // ... still indents down here :(
        .map(|_| ())
        .map(|_| ()) // < enter here!
        // ... still indents down here :D
        .map_err(|_| ())
        .unwrap(); // < enter here!
    // ... indents down here :D

    // ... and subsequent enters stay at the same indent

    0.0f64
        .to_radians()
        .to_radians()
        .to_radians() // force semi on a new line
        ; // < enter here!
    // ... indents down here :D
}

fn tail_end() -> i32 {
    0i32.wrapping_abs()
        .wrapping_abs()
        .wrapping_abs()
        .wrapping_abs() // < enter here!
        // ... still indents here :shrug:
}

[Veykril]

I think we can define these rules statically here instead? https://github.com/rust-lang/rust-analyzer/blob/master/editors/code/language-configuration.json
https://code.visualstudio.com/api/language-extensions/language-configuration-guide#indentation-rules

[DropDemBits]

Oh, I forgot to mention that I tried to add it in the language config file first, but because the onEnter rules are dynamically (re)loaded to include/exclude the comment onEnter rules, the static configuration file isn't used (or at least, that's my best guess as to what's happening).

[Veykril]

Sounds reasonable that this might override the static configuration there
@bors delegate+

[Veykril]

@bors delegate+

[bors]

✌️ @DropDemBits can now approve this pull request

[DropDemBits]

@bors r+

[bors]

📌 Commit c7bd3c6 has been approved by DropDemBits

It is now in the queue for this repository.

[bors]

⌛ Testing commit c7bd3c6 with merge 8011029...

[bors]

☀️ Test successful - checks-actions
Approved by: DropDemBits
Pushing 8011029 to master...