fix(make_entry): improve filename_first support (#3140)

Few pickers with entry makers that relied on `entry_display.create` were
not properly passing the highlight table returned by `transform_path`.
This made the `filename_first` `path_display` option not work as
expected for these pickers.

lua/telescope/builtin/__diagnostics.lua

@@ -132,12 +132,12 @@ diagnostics.get = function(opts)
   if opts.bufnr ~= 0 then
     opts.bufnr = nil
   end
-  if opts.bufnr == nil then
-    opts.path_display = vim.F.if_nil(opts.path_display, {})
-  end
   if type(opts.bufnr) == "string" then
     opts.bufnr = tonumber(opts.bufnr)
   end
+  if opts.bufnr ~= nil then
+    opts.path_display = vim.F.if_nil(opts.path_display, "hidden")
+  end
 
   local locations = diagnostics_to_tbl(opts)
 
@@ -157,7 +157,6 @@ diagnostics.get = function(opts)
     return
   end
 
-  opts.path_display = vim.F.if_nil(opts.path_display, "hidden")
   pickers
     .new(opts, {
       prompt_title = opts.bufnr == nil and "Workspace Diagnostics" or "Document Diagnostics",