minor : fixes for ratoml module

[alibektas]

This is a follow-up PR to #17058.

• Parse errors are reflected as such by defining a new variant called ConfigError::ParseError
• Amend config::ConfigChange::apply_change.
• User config can be detected once again.
• New error collection has been added to store config level agnostic errors.

[alibektas]

rust-analyzer/crates/rust-analyzer/src/config.rs

Lines 3610 to 3612 in bd9758b

	// FIXME: This should be an error
	[cargo.sysroot]
	non-table = "expected"

I would also like to ( since it is relevant to this issue ) ask why this is supposed to be an error. If my assumption is correct it is related to the hyphenated key. If that's the case toml actually allows such keys.

[bors]

☔ The latest upstream changes (presumably #17488) made this pull request unmergeable. Please resolve the merge conflicts.

[Veykril]

rust-analyzer/crates/rust-analyzer/src/config.rs

Lines 3610 to 3612 in bd9758b

	// FIXME: This should be an error
	[cargo.sysroot]
	non-table = "expected"

I would also like to ( since it is relevant to this issue ) ask why this is supposed to be an error. If my assumption is correct it is related to the hyphenated key. If that's the case toml actually allows such keys.

Sprry forgot to reply to this. the error here is that sysroot isn't a table config, so the the non-table key being used here should error