Re-applies https://github.com/zed-industries/zed/pull/30840 This PR re-applies the initial [PR](https://github.com/zed-industries/zed/pull/30840). As it was closed because it was hard to land, because of the many conflicts. This PR re-applies the changes for it. In several cases we were creating multiple display_map snapshots within the same root-level function call. Creating a display_map snapshot is quite slow, and in some cases we were creating the snapshot multiple times. Release Notes: - N/A