fix(multicursor): link default MCursor to CurSearch #41900

Problem: When `MCursor` is linked to `Cursor` it is not easy to
  distinguish the main and extra cursors. Although this is rarely needed
  when editing (since edit is applied at all of them), it is fairly
  needed when jumping between the cursors with `[C` / `]C`.
  Plus different highlighting for main and extra cursor looks
  (subjectively) more pleasent.

Solution: Link `MCursor` by default to `CurSearch`. Linking to an
  existing group (instead of forcing fixed default attributes) makes the
  highlighting more readily useful for user color schemes.
  The `CurSearch` is chosen because:
  1. It is semantically close as "something at cursor". This also means
     that it is not meant to be used for something not at cursor, so
     highlighting for extra cursors should rarely be confused with
     something else.
  2. It is meant to be visible, usually via visible background. This
     is also valuable for showing cursors, as it plays nicely when this
     group is used for coloring extra cursor in Kitty multiple-cursors
     protocol: cursors in Insert mode are usually thin vertical bars
     which require a visible color.

0 files changed, 0 insertions, 0 deletions