fix(inspect): always show priority

Problem: It is not obvious if a treesitter highlight priority shown in
`:Inspect` is higher or lower than the default.

Solution: Also print default priority (`vim.hl.priorities.treesitter`).
Add padding for better readability.

(cherry picked from commit b52ffd0a59)

runtime/lua/vim/_inspector.lua

@@ -184,9 +184,11 @@ function vim.show_pos(bufnr, row, col, filter)
     for _, capture in ipairs(items.treesitter) do
       item(
         capture,
-        capture.metadata.priority
-            and string.format('%s priority: %d', capture.lang, capture.metadata.priority)
-          or capture.lang
+        string.format(
+          'priority: %d   language: %s',
+          capture.metadata.priority or vim.hl.priorities.treesitter,
+          capture.lang
+        )
       )
     end
     nl()