The `inlayHints_lifetimeElisionHints_useParameterNames` config doesn't get passed to the server config struct

[Veykril]

The inlayHints_lifetimeElisionHints_useParameterNames config doesn't get passed to the server config struct, presumably because we also use inlayHints_lifetimeElisionHints which takes priority over the namespace?

[Veykril]

Right so this was just a mistake on my part, we obviously can't use fields on inlayHints_lifetimeElisionHints since that is already set to a string, so we should rename inlayHints_lifetimeElisionHints to inlayHints_lifetimeElisionHints_mode or something similar.

Rename needs to happen here https://github.com/rust-analyzer/rust-analyzer/blob/master/crates/rust-analyzer/src/config.rs#L262, then just run cargo test -p rust-analyzer to have the tests output the vscode package.json.