Render the search UI on a separate row from the breadcrumbs

- In project search, render it above the breadcrumbs
- In buffer search, render it below

Co-Authored-By: Antonio Scandurra <me@as-cii.com>
Co-Authored-By: Max Brunsfeld <maxbrunsfeld@gmail.com>

crates/breadcrumbs/Cargo.toml

@@ -12,6 +12,7 @@ collections = { path = "../collections" }
 editor = { path = "../editor" }
 gpui = { path = "../gpui" }
 language = { path = "../language" }
+search = { path = "../search" }
 theme = { path = "../theme" }
 workspace = { path = "../workspace" }