Support for http files (VSCode REST Client / IntelliJ HTTP Client)

For the developers in our Company we found using http files with VSCode REST Client (https://marketplace.visualstudio.com/items?itemName=humao.rest-client) or IntelliJ HTTP Client (https://www.jetbrains.com/help/idea/http-client-in-product-code-editor.html) the most vendor agnostic way to work with http requests. The file format is very close to the actual HTTP Protocol and is very nice to manage in a VCS like git. Variables make it easy for non-technical people to work with these files but it would be even better if they could use these files in Yaak.

Related: https://github.com/usebruno/bruno/issues/1537, https://github.com/ArchGPT/insomnium/discussions/149