Add hover_line_number color token (#23279)

This enables having a dedicated color for the line number hover state.
That's relevant because line numbers can now be clicked to jump to
cursor location in multibuffers.

Release Notes:

- N/A

---------

Co-authored-by: João Marcos <marcospb19@hotmail.com>

assets/themes/ayu/ayu.json

@@ -59,8 +59,9 @@
         "editor.subheader.background": "#1f2127ff",
         "editor.active_line.background": "#1f2127bf",
         "editor.highlighted_line.background": "#1f2127ff",
-        "editor.line_number": "#bfbdb659",
-        "editor.active_line_number": "#bfbdb6ff",
+        "editor.line_number": "#4b4c4e",
+        "editor.active_line_number": "#cbcccd",
+        "editor.hover_line_number": "#a1a2a5",
         "editor.invisible": "#666767ff",
         "editor.wrap_guide": "#bfbdb60d",
         "editor.active_wrap_guide": "#bfbdb61a",
@@ -429,8 +430,9 @@
         "editor.subheader.background": "#ececedff",
         "editor.active_line.background": "#ececedbf",
         "editor.highlighted_line.background": "#ececedff",
-        "editor.line_number": "#5c616659",
-        "editor.active_line_number": "#5c6166ff",
+        "editor.line_number": "#b0b3b5",
+        "editor.active_line_number": "#313435",
+        "editor.hover_line_number": "#62686a",
         "editor.invisible": "#acafb1ff",
         "editor.wrap_guide": "#5c61660d",
         "editor.active_wrap_guide": "#5c61661a",
@@ -799,8 +801,9 @@
         "editor.subheader.background": "#353944ff",
         "editor.active_line.background": "#353944bf",
         "editor.highlighted_line.background": "#353944ff",
-        "editor.line_number": "#cccac259",
-        "editor.active_line_number": "#cccac2ff",
+        "editor.line_number": "#575c6b",
+        "editor.active_line_number": "#e1e3ea",
+        "editor.hover_line_number": "#b2b6c8",
         "editor.invisible": "#787a7cff",
         "editor.wrap_guide": "#cccac20d",
         "editor.active_wrap_guide": "#cccac21a",