Feature Request: Commands to toggle feature(s)

It would be nice if you could run a command to toggle specific features by automatically editing the rust-analyzer.cargo.features setting. For instance, the commands could be like:

1. "Enable all features": This would set the rust-analyzer.cargo.features setting to "all".
2. "Enable feature...": This would cause a text box to appear where you could write the feature. That would then be added to the feature list in the rust-analyzer.cargo.features setting.
3. "Disable all features": Would simply clear the setting.
4. "Disable feature...": Should ideally show the list of features already present in the setting and allow you to choose one to disable.

You could also imagine that a code action could be added to #[cfg(feature = "...")] attributes which would enable/disable the feature.

The server should then restart automatically after running this command (which is required whenever editing the setting).