Closes https://github.com/zed-industries/zed/issues/13756
Closes https://github.com/zed-industries/zed/issues/61572

Last window client capability we were missing!
<img width="1557" height="159" alt="image"
src="https://github.com/user-attachments/assets/2cca5d92-a28e-4262-8f55-89f582782bbc"
/>

Two features are connected to each other, as most of the commands result
in opening a document:


https://github.com/user-attachments/assets/661aae88-7af9-4173-9f6a-2fd11dbec675


Release Notes:

- Added support for LSP command executions and showDocument requests