1031: Move most things out of ra_ide_api_light r=matklad a=detrumi
This moves everything except `structure` out of `ra_ide_api_light`. So this PR and #1019 finish up #1009, whichever is merged last should probably remove the `ra_ide_api_light` crate.
Also, `LocalEdit` was removed since it wasn't used any more.
Co-authored-by: Wilco Kusee <wilcokusee@gmail.com>